GB1564822A - Electrical musical instrument - Google Patents

Description

(54) ELECTRICAL MUSICAL INSTRUMENT (71) We, SUNE HARLEY BERGMAN, and ERIC UNO SEGER, both Swedish subjects, of Vommedalsvagen 42, S-430 50 Kallered, Sweden and Saggatan 62 S-414 67 Goteborg Sweden respectively do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to electrical musical instruments comprising means for generating electrical signals corresponding to musical tones or sound effects and members operable by a player for collecting signals from said means for further treatment and/or transmitting to a sound reproducing device.

The means for generating electrical signals can in a manner known per se comprise a main oscillator, a so-called master oscillator, and a predetermined number of frequency dividers coupled thereto, but other devices for generating the electrical signals can be used. The electrical signals generated in said device need not have, and preferably do not have the same frequency spectrum as the tone or sound effect which is eventually to be reproduced in a sound reproducing device, since the original signals can and preferably are intended to be modified or transformed in accordance with the parameters of the reproducing device. It may even be possible to combine original signals according to a simple code, in accordance with the tone and sound effects to be produced. The members for collecting or selecting signals can comprise, for instance, keys of a keyboard of any ordinary type.

It is usual in instruments of the aforementioned type to use members which simply act to transpose between different keys, said members being not described in a detailed manner in the present connection.

Known electrical musical instruments of the aforementioned type do, however, have various limitations from various aspects.

In a known instrument (see U.S. Patent 3,099,700) there are circuit arrangements such that when, for instance, the keys of a keyboard are operated not only the tones corresponding to the operated keys which constitute the lead or melody part sound but also and simultaneously tone forming harmonies with the tones corresponding to the operated keys are selected and reproduced. The harmony patterns obtainable with these known circuit arrangements are, however, mutually different harmonies or chords within an octave of a particular key. Another limitation exists with respect to the possibility of separately treating harmony tones intended to belong to separate subparts, and this means that in the known instrument it is not possible to assign a special tone character to each sub-part and thereby to obtain a musical effect corresponding to orchestral music.

It can further more be said that the known device because of the necessity to provide at least one special mechanical contact for each note in a harmony is, in practice, limited to the generation of harmonies containing only a few notes. The high number of mechanical contacts required in the known device is, on the whole, a drawback which does not only make the instrument expensive to buy and maintain but also affects its functional reliability.

As considered from another aspect it can be said that insofar as instruments according to the aforementioned type are arranged to generate an accompanying bass part by control by means of a pedal contact instruments of the type hitherto known have had the drawback that they are limited as to the possibilities in a sequence of accompanying notes comprised of bass notes to let a great number of mutually different notes be included. Usually, the number of notes included are limited to three viz. the fundamental note the third and the fifth of the key in question which limitation contributes to the fact that the music performed is of less varied and expressive character.

According to a further aspect, the instruments of the aforementioned type when arranged as rhythmical instruments have the drawback that they do not permit the production of rhythms and rhythm effects with the richness in variety which is nowadays more often demanded and which is present in an ordinary orchestra. This depends inter alia of the use of automatic so-called rhythm apparatuses which usually are driven by an oscillator, i.e. an electronic motor which can be set to a limited number of different tempi and rhythms but which thereafter must be accurately followed by the player which, on one hand, is difficult and on the other hand leads to a music which is not felt as living.

One object of the present invention is to avoid the abovementioned drawbacks of the electrical musical instruments known before and to provide an instrument which makes it possible for a single player to produce music having the richness in variety which otherwise can be found only in music produced by an orchestra.

According to the invention an electrical musical instrument has means for generating electrical signals corresponding to musical notes and members adapted to select certain of the signals for further treatment and/or for transmission to sound reproducing apparatus, and is characterised by a circuit responsive to operation of a single contact to cause a sequence of at least four notes in the scale of a certain key to be played automatically one after the other.

The invention may be carried into practice in various ways and certain embodiments will be described by way of example with reference to the accompanying drawings in which: Figures 1 and la together show a circuit diagram of a part system, a so-called "harmony system" which on the performance of a first "lead" part simultaneously produces notes forming harmonies or chords, together with the notes in said lead part.Figure 1 also shows a number of signal controlling flip-flop circuits; Figure 2 and 2a together show a circuit diagram of another part of the system, the so-called "bass system" with the purpose at repeated operation of at least one pedal contact of obtaining sequences of bass notes which sequences are usable as accompaniment in various keys; Figure 2b and 2c show contact means for controlling the system according to Figures 2 and 2a; Figure 3a is a circuit diagram for a key selector comprises in the instruments; Figure 3b shows a number of signal controlling flip-flop circuits in addition to those shown in Figure 1.

Figures 4-6 show circuit diagrams for a further part system, the so-called rhythm system, which in each phase of a musical score makes it possible freely to choose tempo and rhythm; Figure 7 is a block diagram over various functions of an instrument according to the invention Figure 8 shows circuits for obtaining a squence of bass notes; Figure 9 is a circuit diagram of a device for correct and uneven rhythm operation in any phase during the performance of a musical work; and Figure 10 is an example of a harmony pattern which can be in an instrument according to the invention.

The signal treatment systems which by themselves or in combination can be used in a musical instrument according to the invention will first be shortly described.

The musical instrument according to the invention can be programmed so that it is suitable for the performance of popular music incuding evergreens, schlagers, songs, lighter jazz, etc.

Music can be produced according to other tonal systems for example those based on the twelve note scale, and the pentatonal system. The instrument can have the shape of an electronic organ which, besides, can of course be arranged to be played in a conventional manner after shutting off the automatic systems for harmony, bass and rhythm patterns. The instrument can be provided with a keyboard comprising five octaves, 16', 8', 4', 2', and fifth pitches conventional organ stops, percussion, sustain interlocks for various sound combinations, vibrato, various volume controls and volume pedal. In a stereo embodiment the melody line and the accompaniment may be produced in different loud-speakers.

In an orchestra score each harmony part is usually assigned to a particular instrument. The lead part, I:st part, can for instance be a clarinet part (sometimes a song part) in certain popular music, the 2:nd part can be a saxaphone part etc. An ordinary orchestra arrangement is written according to the conventional theory of harmony, the teaching of which has taken years for the composer to acquire. It is possible to produce music which resembles orchestral music with all parts performed simultaneously without any need for the player to have knowledge of the theory of harmonies and orchestration. To provide the music it is sufficient for the player to use only one finger of each hand.

This has been made possible by the provision of harmony patterns which are based on fundamental portions of the theory of harmony and which are predetermined according to a program for each scale note of each key it being possible by electronic couplings to separate the various parts from each other and treat them individually, so that one part can be different in sound character, volume etc., than another part.

Finally, all parts are combined again so as to form the end product which can be reproduced by means of loud-speakers.

The lead part can be played by means of an ordinary key-board and the selection of key can be made by means of a set of buttons comprising twelve buttons one for each key. Moreover one or more elongated bars pertaining to different harmony variations can be provided extending for instance parallel to the keyboard. It should be pointed out that the instrument is so arranged that when a note of the lead part is played corresponding notes of the sub-parts are played automatically simultaneously. Although this way of playing is simple it is nevertheless possible to perform rapid multi-part playing passages which hitherto have not been possible to perform on a musical instrument of the traditional type, not even by the most qualified musician.

The manually operable means for the selection of keys and harmony variations can suitably be arranged in such manner by electronic couplings or mechanical arrangements so that a chosen key or harmony variation, respectively, is maintained as to its function from the moment at which the corresponding setting means was operated and until another setting means is operated. Thus, during this time interval the player has his hand free for the performance of other control functions without the playing having to be interrupted.

The above-mentioned setting means for the selection of key and harmony variations in the harmony system can also be used for controlling the bass system. The purpose of the bass system is to provide an accompaniment similar to that which is usually provided by means of a bass instrument, for instance a contrabass, an electrical bass etc. in most orchestras essentially for the purpose of supporting the harmony sounds of the orchestra.

The bass system is arranged to generate a sequence of notes for each key said sequence being based on the conventional theory of harmony, and the bass patterns thus obtained are programmed into the electronics.

By this method a bass melody can be provided which fits to the lead part with sub-parts simultaneously performed by means of the harmony system. The bass system is suitably operated by means of a pedal device. By pressing a pedal the player selects a bass note which is brought to sound and die out in a similar manner as the tone of for instance a contrabass or electric bass.

For each new pedal operation a new bass note in said sequence is obtained. Said pedal operations can be effected by means of a single pedal contact or alternately by means of two pedal contacts, for instance a heel and a toe contact according to the player's intentions.

For supporting the lead part and the subparts in popular music which mostly is written in 4/4 rhythm the bass part can be marked in each or every second fourth.

However, the bass system permits the marking in many other ways for the performance of, for instance, latin american music.

Each 16th of a bar can be controlled and for this reason very varied rhythms can be obtained. The rhythm system can control various types of electronic rhythm signal generators, for instance for so-called whisk accompaniment, hi-hat, maraccas, bongos, claves, rhythm guitars etc. The control can be effected by means of a special device but suitably by means of the same pedal device which is used for controlling the bass system according to the above. In this case the pedal device can provide a complete accompaniment ("comp-pedal"). Other rhythm effects which can be operated manually is, for instance, a bass drum, or a cymbal.

Different rhythm patterns can be brought into the program successively by the player by operating buttons in a special set of buttons at the instrument panel and the rhythm can thereafter be chosen and modified according to the taste of the player. Since the rhythm is always directly controllable by the player himself and is not dependent on any automatic, motor or oscillator driven so called rhythm apparatus as in certain previously known instruments the player is not limited to given tempi and predetermined rhythm patterns but can, as a beginner or as an experienced musician, easily and in every phase provide the accompaniment which according to his own taste is the best in the given musical connection.

The above-mentioned harmony, bass and rhythm patterns are intended to be used separately or together in any optional combination since a large part of the components can be common. In a musical sense they complete each other since the first mentioned system relates to a melodic/harmonic tone system and the other systems relate to an accompaniment thereto. Thus, a beginner can attain a good musical result which has hardly been possible with previously known and traditional musical instruments. Even virtuosi can obtain a result which a single person cannot possibly obtain when playing a traditional musical instrument and this because of natural technical limitations.

The operation of the instrument is effected by means of a few components only and according to traditional fundamental rules.

In a fully equipped state the instrument is intended as much as possible and by simple playing means to substitute for a full orchestra with its various functions such as, for instance, solo, melody, sub-parts, bass melody, rhythmic accompaniment etc. This without necessitating the use of automatic apparatus having predetermining functions such as for instance tape recorders, automatic beat instruments (electronical or mechanical) etc.

The chosen harmony, bass and rhythm patterns can be of general nature. The pattern can, however, easily be modified in various respects according to the personal concept of the designer or the player.

During playing of the instrument the lead melody, sub-parts, rhythm type, tempo, key etc. can be controlled all the time and treated individually and the player can also influence the result as to volume and the sound character of the instrument.

The orchestral result is attained in spite of the fact that the player need only use one finger of one hand for playing the melody, one finger of the other hand for controlling the harmony and one foot for performing the desired accompaniment by means of a special pedal for this purpose.

The circuit arrangements of the embodiments shown on the drawings comprise a great number of different electronical components which are conventional per se and whose connections in the circuits are so evident and clear from the drawings that they need not be more closely described in the present detailed description which, therefore, will be limited to describing substantially only the functions of the circuits and what is obtained by said circuits.

The harmony pattern system. The device according to Figs. 1, Ia, comprises twelve tone generators FD of usual type each consisting of a master oscillator and a number, of frequency dividers for each scale note within an octave of the instrument. A note is selected by pressing a key of a keyboard. The signals obtained from FD can be rich in overtones and can consist of for instance square or sawtooth signals. In Fig. Ia keyboard keys KT1 .

KT13 . . . KT25 are marked by the contacts operated by such keys. The keyboard in question thus comprises three octaves, but the invention is of course not limited to this number.

Simultaneous keying of several channels is effected by a single contact function (contact closing) for each operation of a key KTl-KT25. This is possible thanks to the use of diode gates thus saving considerably more expensive contact/conductor arrangements. Also the operational reliability is thereby increased. What has now been said is valid also for other means of operation which will be more fully described in the following for instance for the selecting of keys, for modifying the harmony etc.

Now, as regards the leading (melody) key note it should be pointed out that this note can be registered in different manner, for instance for 32'. 16', 8', 4', 2', fifth sustain and percussion: 4', 2', fifth. The scheme can be said to presuppose a simplified case (straight) simple tone signal. All permanent dc voltage levels are chosen such that the diodes in question open or close at the closing or opening by keys or other members of operation. A=+15V, B=+6V.At the operation of the key KT I positive potential is tranmitted via a resistance R12 to a diode D5 which is thus made conducting so that a tone signal from a frequency divider of F, D corresponding to a certain tone, in the example the note F, is supplied to the terminal end LMI via the resistance R 13 and the capacitor C4 the side of which removed from the terminal being coupled to earth through the resistance R14. From the terminal LM1 the signal passes to a sound reproducing device directly or indirectly via shaping circuits which determine the tone character, and/or amplifiers. Said shaping circuits and amplifiers, respectively, are not shown in the drawing since thay can be of conventional contruction.The shaping circuits can for instance comprise a combination of filters adapted to cut a signal rich in overtones from the frequency divider FD so that the reproduced tone obtains the desired frequency spectrum and desired amplitudes of its overtones. The signal from LMI is intended to be comprised in the "lead" part of melody part. This part will be accompanied by a number of sub-parts according to the following.

By the operation of KTI positive potential is also carried via a number (9) of resistances R2 to a corresponding number of diodes Dl and D2 which thereby are made conducting so that tone signals from the frequency dividers of FD are supplied to a harmony pattern circuit positioned within the field M1--M12 which is marked by dotted lines.

This is coupled in accordance with certain harmonically conventional and general principles. The circuit can, however, be varied in various manner and is thus not limited to the embodiment shown in the drawing. The instrument is intended to comprise twelve harmony pattern circuits M1--M12 one for each key within one octave. The number of harmony pattern circuits can be limited to twelve independently of how many octaves of the lead part the instrument comprises.Of these harmony pattern circuits at least five, suitably most of them and, if desired, all of them can be mutually different in such a manner that if the instrument is set (transposed) to a certain key and if one after the another of the keys KTl-KTl2 within an octave of the scale is operated sub-parts forming harmonies together with the lead part are reproduced together and simultaneously with the leading part, at least five, suitably most of and, if desired, all these harmonies being, if desired, mutually different. The reproduced harmony for the key KTI in the key setting according to Fig.

I, according to which the fundamental tone is F, is determined in a manner described more closely in the following of the harmony pattern circuit Ml. The harmony for the next key KT2 corresponding to the lead tone Gb in the scale is determined by the harmony pattern circuit M2 (not shown) for this key etc. Thus, each of the twelve harmony pattern circuits determines only one harmony in the succession of harmonies (the harmony pattern) which is assigned to the twelve notes in the scale of notes of the key to which the instrument is set at the time in question. In the succession of harmony pattern circuits Ml, M2 etc.

each circuit can, but need not, contain the same series of a predetermined number (27 in the shown embodiment) of input-output connections as all the other eleven harmony pattern circuits but with the various inputoutput connections being shifted one step to the right (or to the left) in each harmony pattern circuit in said succession and with the last input-output connection in one circuit becoming the first input-output connection in the next circuit etc. (cyclical permutation). However, each harmony pattern circuit in said series of twelve circuits can be individually designed in order to provide extremely varied harmony patterns if desired.

In the harmony pattern circuit Ml the tone signals are distributed and pass via R3 to C1. As appears from the scheme each key selects from the tone generator FD "its proper" tone signal (for the lead part) but also nine further tone signals (sub-parts) in the same manner. It is among the latter that the tone signals for four different parts are selected by the harmony pattern according to the shown system. These parts can suitably be for instance the third, the fifth, the sixth and the septima, if the lead tone is the fundamental. In relation to the fundamental, i.e. the note F in the example, the sub-parts are represented frequencywise downwards of the succession of notes Eb, D, Db, C, B, Bb, A, Ab and G. In the same manner the lead note E will receive by transposition the notes D to Gb, Eb from Db to F etc.The number of sub-parts need not be limited to nine but can be higher or lower and be of higher or lower frequencies. The scheme shows that this group of nine is thereafter distributed via the capacitors Cl to seven part units each containing four subparts. The part units are in operation only one at a time and which of the part units is in operation is determined by the setting of flip-flop circuits FLl-FL7 shown at the bottom of Fig. 1, the number of said flipflop circuits corresponding to the number of part units and the functions of which appears from the following.

Considering the functions of the four components Cl, D3 and R5 of for instance the first, left part unit it appears that the four R5-resistances of the group are connected to the one collector of the flipflop circuit FLl. The flip-flop circuits are so connected that when one of the flip-flop circuits is in b-position all the other are always in the a-position depending of the diode arrangement at the operation buttons MT2--MT13 according to Fig. 3a and the operation key MT1 (Fig. 1).If the flip-flop circuit FLI is brought into the b-position the one transistor is conductive which results in that the four diodes D3 in the first left part unit is likewise conductive while the other diodes D3 (24 in number) are nonconducting depending of the function of R6, R10 and C5 which determine the fixed dcpotential level of the four horizontal conductors La-Lb. From this it appears that in the example according to Fig. 1 the tone signals Bb, G, D, Db, and only these signals are transmitted to La, Lb, Lc and Ld. The signals of La and Lb pass via R8a and R8b, respectively, and C3a and C3b, respectively, directly to the terminals SMI and SM2 and form sub-parts, the 2nd and 3rd parts, respectively, thus in the present example, Bb and G.One of the signals on Lc and Ld are stopped depending of the position of the flip-flop circuit FL8. This circuit is connected to the points of connection between C2a, C2b and C4a and C4b, respectively, via R7a, R7b, respectively. If the key M1 is operated the left hand transistor of FL8 becomes conducting which results in that one diode D4b becomes conducting and the signal passes further to SM3 via C3c and forms the 4th part Db. If the flip-flop circuit is brought to change over by means of M1 the other diode D4a will instead become conducting so that SM3 receives the tone D. The key MTI is used to change from major to minor key. If the output terminal SM3 is blocked there remains SUM 1 and SM2 which together with the lead tone form the three-tone chord for playing in major key.A similar function is performed if SM2 is blocked at which occasion three-tone chords for playing in minor keys are formed. The blocking of said output terminals can simply be effected by means of interruptors which are not shown in the drawings which interruptors can be operable by means of a ''major'-bar and a "minor"-bar, respectively, which are not shown either but can consist of elongated members arranged along a row of key selectors.

From the output terminals SM 1, SM2 and SM3 the respective signals can in an analogous manner as the signal from the output LMI be carried via shaping circuits and amplifiers to a sound reproducing device. The shaping circuits can in this case be adapted to give individual sound character to each terminal's signals so that the performed harmonies obtain orchestra character (each different instrument assigned to one part). Furthermore, in order to obtain stereo effect it is possible to let for instance the lead part from LEM 1 be reproduced by one loud-speaker and the sub-parts from SM1--SM3 to be reproduced in another loud-speaker.

The note example shown in Fig. 10 indicates the harmonies, i.e. the harmony pattern which is obtained in one embodiment in which F is selected as the key F and a chromatic scale is played. The upper system indicates the notes of the leading part, the next lower system indicates the 2nd part etc. The 4th system from above indicates the notes of the 4th part if the contact MTI is not closed and the 5th system indicates the notes when MTI is closed.

In the example of Fig. 10 only eight (of properly twelve possible) harmony groups have been used. This is because notes belonging to two keys can be said to be included in each group. This is possible especially if these two keys have a very remote harmonical relationship. Thus, it is possible to place for instance the E and F keys in the same function. Key E formations are often used as harmony variations or harmony transitions in the key F so that it can be practical for a melody carrying lead part in F to obtain a harmony pattern formed by subparts in which pattern such key E formations are included and this is also in agreement with usual harmonizing practice. Besides, it can be said to be desirable from the point of view of cost saving to assemble several key functions in the same circuit.It should be pointed out that the harmony pattern circuit, the number of sub-parts, the distribution thereof, the number of input- and outputs tone signals etc. need not be limited to what is shown in the drawings.

The manner in which the selection of a desired key is effected in the harmony system shown in Figs. 1, la will appear in connection with the following description of the bass pattern system and the rhythm pattern system with reference to the Figs.

2razz Fig. 7 shows a block diagram of the bass and rhythm pattern systems certain functional relationships between these systems and the harmony pattern system being also indicated. Before describing the bass and rhythm pattern systems it should be pointed out that each flip-flop circuit in the circuit according to Fig. 1 (FLl-FL8) as well as in the circuit according to Fig. 3a (FL9--FL14) are arranged to provide a holding function which is necessary in order to make possible rapid changes in the selection of keys and thus for avoiding interruptions in the progression of harmonies and the bass melody. Moreover, a good time interval between the manual operations of various buttons and bars more closely described in the following is obtained.

Reference numeral I in Fig. 7 designates key selectors which are more clearly shown in Fig. 3a where twelve key selectors are represented by their respective contacts MT2-MT13. These contacts can, for instance, be operable by corresponding buttons arranged in one or more rows at the instrument panel in such a manner that they can easily be actuated by the left hand of the player at the same time as the player plays the melody line and accompanying notes with his right hand on a keyboard for this purpose.

The contacts MT2-MTl3 cooperate according to Fig. 3a with diode circuits Dl 32-D207.

In Fig. 7 the reference numeral 2 designates harmony variation selectors. In a large part of the musical repertoire certain harmony or chord variations are used in addition to the basic harmonies, for instance harmonies having diminished third, diminished fifth, augmented fifth, etc.

corresponding to the conventional designations "minor", "dim" "+", etc. In order to permit such variations the instrument is provided with operation keys MT14 and MT15, Fig. 2b, which can be used in addition to said key selectors. The output connections P9--P12 of the device according to Fig. 2b are shown at the lower part of the circuit according to Fig. 2a. It is a general feature of all drawings that contacts having identical designations are intended to be directly connected to each other. Harmony variation selectors need not always be present.

In Fig. 7 the reference numerals 3 and 4 designate bass pattern selectors and bass patterns. The bass patterns can be of two types, one which can be disposed "freely" without taking consideration of certain predetermined positions in the sub-division of the bars such as the positions for the third and the fifth and one which has predetermined positions for these chords. In the following the design of such a bass pattern used in connection with harmony variation selectors shall be described. If the latter is not used the harmonies are determined by the key selectors which provide only fundamental harmony bass patterns, for instance in major keys.

The bass pattern determining unit M21 in Fig. 2a comprises a number of "horizontal" conductors connected to a number of "vertical" conductors by means of diodes Dl 5-D74 in accordance with predetermined patterns which have been chosen beforehand in order to provide bass melody phrases of a general character.

It should be mentioned that the bass pattern according to the embodiment provides a fundamental harmony in major keys. Bass patterns in minor key presuppose the use of harmony variation selectors by which the harmonies can be changed (modified) which is effected by means of manually operable contacts Ka, Kb and Kc according to the scheme in Fig. 8, which contacts are adapted to connect and disconnect resistances in the manner shown in Fig. 8 which results in diminishing or augmentation of the output potential at the output terminals P3, P7 (third) and P5 (fifth), respectively, of the ring-counter.

This is made possible since it has been determined in advance that each bass melody phrase will have the third and the fifth, respectively of the fundamental chord falling in the third/seventh and fifth part, respectively of a phrase comprising two bars in a 4/4 rhythm.

In Figs. 2 and 2a OK1 designates a bass pattern selector which consists of a multipole switch for selection as desired among various bass patterns, i.e. various sequences of bass notes. The switch is a 7pole switch. It is connected to output terminals Pl-P8 of a so called ring-counter which is shown at the bottom of Fig. 2a and which consists of a cascade circuit of a number of bistable circuits. The ringcounter counts in accordance with conventional musical bar divisions, for instance two bars in 4/4rhythm, 4 bars in 2/4rhythm, etc.

The reference numeral 5 in Fig. 7 designates flip-flop circuits for transposition of keys. These circuits are designated by FL13 and FL14 in Fig. 3b. One collector resistance in each circuit has been substituted by a relay Rel and Re2. Each of these relays control a contact function (closing) the purpose of which is to connect the capcitors C65 or C66 in parallel with one of the frequency determining capacitors C19 in the oscillator BO according to Fig. 2.

These capacitors determine the choice of key among three adjacent keys. If none of the capacitors C65 and C66 is connected into circuit a certain key is selected, for instance, C. The base resistances R61. R66 in PGI in Fig. 2a are set in a manner which will be more closely described below in connection with the detailed description of the tuning unit 7 in Fig. 7. If C65 is connected in parallel to Cl9 the key will be B to give a transposition of a half-tone which is also effected for all tone frequencies within the same key, but with maintained tuning positions for R61--R66.

When C66 is connected in parallel to Cl9 the key Bb is obtained which is a further half tone from B, i.e. a transposition by a full degree from the starting position C key.

The reference numeral 6 in Fig. 7 designates flip-flop circuits for keys. These circuits are constituted in Fig. 3b by flip-flop circuits FL9--FL12 each connected to one key group PGl-PG4, of Figs. 2 and 2a. In accordance with what has been described above three different, adjacent keys are obtained by transposition. This is true for each of the key groups PGI--PG4 to give a choice of twelve keys.

The block designation 7 in Fig. 7 relates to a tuning unit for the bass notes. This unit comprises, see Fig. 2a, trim potentiometers R61--R86 arranged in four groups each having a diode output D75-D78 to the base of one transistor of the oscillator BO, and each with one additional diode D79-D82 connected to the respective flip-flop circuit FL9--FL12, Fig. 3b, via the outputs G3- G6. The trim potentiometers allow tuning of the tone frequencies which are used in the musically determined bass tone pattern.

Different groups of trim potentiometers allow tuning of all bass tones of the bass patterns belonging to the group. If it is supposed that the potentiometer group PGI is used for the keys C, B and Bb, R61 R66 can be arranged for tuning the bass tones C, A, G, F, E and D respectively, which tones can occur in bass patterns of various appearance in the key or tonality C.

The same potentiometer group can, however, also be used for tuning in the keys B and Bb to which transposition can be effected according to the above in that the capacitor Cl9 in BO is increased by C65 or C66 in FL13 and FL14, respectively, of Fig.

3b. These capacitors are connected in circuit when the corresponding contacts are closed in the series MT2--MT13, Fig. 3a.

This proceeding is merely a transposition of the bass notes A, G, F, E and D included in the key C to the corresponding notes in the keys B and Bb.

The groups PG2--PG4 do not influence the tone frequency of BO in the preceding example relating to PGI, since the diodes D76-D78 are held of by the collectors in G3, G4 and G5, Fig. 3b, being at "earth potential" and via the diodes D8WD82 bring the mutually common potential connection points of PG2--PG4 to the same potential. The groups PGl-PG4 have different bass melody patterns with the exception however, that the "vertical" conductors from the ring-counter outputs P3/P7 and P5, respectively, are connected so as to provide the third and the fifth, respectively, of all fundamentals. The remaining bass notes which are determined from the outputs P1, P2, P4, P6 and P8 can be combined in different ways.The groups PG2-PG4 are arranged in the same manner as the groups PGI. If the group PGI is assigned to the keys C, B and Bb the group PG2 to the keys A, Ab, G, the group PG3 to the keys Gb, F, E and the group PG4 to the keys Eb, D, Db it can be seen that when playing a musical composition in, for instance, the key C in which the harmony functions tonic (C-chord) dominant (G- chord) sub-dominant (F-chord) and dominant-dominant (D-chord) are usedi.e. the elementary harmony functions mutually different bass melodies are obtained for these harmony functions.The accompaniment will in this manner be rich in variation and living and gives the impression of a fully independent development or progress of the parts in correspondence to the bass accompaniment executed in a live orchestra.

The block designation 8 in Fig. 7 relates to the bass tone generator of the instrument.

The bass tone is generated in the bass oscillator BO, Fig. 2a. In order to change the frequency the value of one bass resistance (R61--R86) is varied, and a capacitor C65 or C66 is connected as described above. BO consists of an astable multivibrator (A MV). The bass tone is frequency divided in BFI and BF2.

The designation 9 in Fig. 7 relates to a gate stage for the bass tones and designated by PR in Fig. 3a. Figs. 2, 2a show on one hand a pulse stage which can be controlled directly by pedal contacts PD (Fig. 2c) and on the other hand a switching stage PS intended to give to the bass tone signal entering through C27 and C28 a falling amplitude as occurs when playing a string, for instance. The pulse stage is used only on special occasions, for instance for unusual rhythm types. The contacts of the pedal PD are in such cases connected directly via N NP. In other cases there is an interruption between N and NP and the base of the transistor T25 is instead connected at Q to one of the pulse outputs Fl-F3 of the rhythm pattern system according to Fig. 4 which will be more closely described hereinbelow.

The switching stage PS is provided at the collector of the transistor T25 with two diode outputs D13--D14 each connected to one RC-circuit, said RC-circuit having mutually different time constants. In the one case the RC-circuit consists of R55, C29 and C3 1. The capacitor C31 can be shortcircuited by the contact OK3 whereby the time constants of the circuit are changed. In the other case the RC-circuit consists of R56 and C32. The first-mentioned RCcombination provides a slowly decreasing amplitude of the end portion of the bass note and the other RC-circuit provides a starting attack (tone start transient). These RC-combinations are connected via Dl 1 and D12, respectively to the variable resistance R53 between -A and "earth".After a predetermined period of decreasing amplitude the diodes are blocked successively. The capacitors C26a and C30 between the output BM and "earth" have only coupling and filter functions. At BM a filter known per se is connected which filter is arranged to provide a suitable overtone spectrum.

The reference numeral 10 in Fig. 7 relates to an amplifier which can be of conventional type. The block 10 also indicates a sound reproducing device for the bass and rhythm section.

The block 11 in Fig. 7 relates to pedal functions. These are designated by PD in Fig. 2c. The contacts referred to can, it is true, be adapted to be operated manually but they are preferably arranged to be operated by one of the player's feet. The pedal device comprises two (or more) mechanical suspended pedals PK and PT intended to be operated by the front part, toe contact, and the rear part, heel contact, of the foot. The unit can be operated by the heel only, PK, by the toe only PT or alternately. The movements are effected rhythmically wholly in accordance with the tempo variations desired by the player. If only the heel contact is to be used the sole should rest on a pedal, PT, for this purpose and the opposite is true if only the sole contact is to be used. The contact functions are so arranged that the points PU and PN are alternately connected to "earth" on pedal movements. The point N which is connected to the "earth" at every actuation is connected via R91 to the collector of a transistor T2 in a switching stage at the left in Fig. 2a. On operation the collector receives a positive pulse, since C35 has been short-circuited for a short moment when N is connected (switched) to "earth". In resting or idle position N receives positive potential +A via R89.

The positive pulse at the collector of T2 is passed via a small capacitor C36 to the base of a transistor Tl whose emitter is connected to the emitter of the one transistor T3 of the first of a number of multi-vibrators 1-VIll which are mutually coupled in a manner such that they form together a known so called ring-counter.

As to the function of the ring-counter reference is made to the literature: Schaltbeispiele, ITT, 1967, Ringzahler, page 43. Briefly explained the function of the ring-counter is to produce for each switching at one and the same switching point the coupling into circuit of one and only one channel at a time in a group (ring) of channels and to automatically start a new series of couplings into circuit after all channels in the group has been coupled into circuit one after the other.

The contact means PK of the pedal device PD, Fig. 2c, has an extra contact having the output NS which is connected to the part VIII of the ring-counter at the base of the transistor T18, Fig. 2a. In this manner it will be possible for the player to interrupt a bass melody which has been started and to immediately set the ring-counter to "zero" by connecting to "earth", the base in the second transistor of the last part VIII of the ring-counter so that the next actuation will always couple the first part I of the ring-counter into circuit.

This function is best made possible mechanically in that the pedal PK is arranged so that it can be lifted an extra distance so that the extra or auxiliary contact co-operating with NS is closed.

Since the base of T18, Fig. 2a, is thereby connected to earth potential is obtained at P8 as a preparation for the next pedal operation, when part I of the ring-counter is coupled into circuit.

The ring-counter designated by 12 in Fig.

7 comprises the ring-counter parts or bistable stages 1-VIlI having outputs Pl- P8. In each movement the state of one of these outputs is different from the state of the other outputs in such a manner that the +potential of this output is merely equal to +A, while the others have a potential of about +4V. This state is changed at every actuation of the ring-counter so that the output of the next ring-counter part receives the same state as the preceding part. Only the higher + potential is capable of influencing the circuits connected to Pl- P8.

The output signal from X and XI at the part I of the ring-counter has for its purpose to block and open, respectively, the diodes D7 and D8 of the device BO which is connected to the frequency dividers BF1 and BF2. If D7 is blocked the oscillator's own leading tone frequency will not be present at the output BU of the bass tone generator but the leading frequency from BFI since D8 is always conducting when D7 is blocked, and vice versa. In this manner a bass note is obtained which is lower by one octave, when P1 has the appropriate potential.

In Fig. 7 13 designates pulse generators for controlling the rhythm pattern circuit, described below, from the pedal device PD via the ring-counter 1-VIlI.

The block 14 in Fig. 7 relates to the rhythm pattern circuit which is more clearly shown in Fig. 4. At the bottom of this Fig.

sixteen pulse generators in the form of transistor circuits having the transistors T26--T41 are shown. The transistor circuits form four mutually identical groups. These groups receive a drive potential in the form of pulse potential from the outputs Pl, P2, P3, etc. of the ring-counter in a successive manner. Since only four groups exist (corresponding to a whole 4/4-bar) while the ring-counter has eight outputs (corresponding to two whole 4/4-bars) Pl and P5 are connected to produce +potential to the first pulse generator group, P2 and P6 connected to produce +potential to the second group, etc.The +potential from the ring-counter is coupled via diodes Dlle- Do 17 and the Zener-diodes Z2-Z5 to hold the outputs Pl-P8, Fig. 2a, not lower than +4V. The collectors of the transistors T26 T41 which in idle position has positive +potential are each via one capacitor C39 C54, respectively, connected to one "vertical" conductor in a rhythm pattern circuit X41 which also comprises a number, three in the shown embodiment of "horizontal" conductors, each connected to one terminal FI-F3. The horizontal conductors are via diodes D87--D109 connected to vertical conductors according to special patterns for each of the horizontal conductors in correspondence to the rhythms to be produced by the rhythm circuit.

Each of the vertical conductors is connected to a resistance R10e-R115 which by means of a resistance R170 is biased to about 2V.

When each of the transistors conducts a negative pulse occurs at the corresponding "vertical" conductor as counted from left to right for each 16th of a whole measure according to the note marking in Fig. 4. The vertical conductors' connection via diodes to the horizontal conductors can be effected according to other rhythm patterns than those according to Fig. 4 and the number of horizontal conductors can vary. The horizontal conductors receive pulse series which are mutually different and correspond to the desired rhythm types.

In Fig. 7 the reference numeral 15 relates to rhythm pattern selectors corresponding to the contacts OK4-OK6 in Fig. 4. By means thereof pulses according to any of the rhythm patterns according to a predetermined program can be transmitted via the contacts Fl-F3.

In Fig. 7 the block 16 relates to a signal treatment stage generally designated "gate stage". In Figs. 5 and 6 circuit diagrams for two such stages are shown. The device according to Fig. 5 is a switching device which is controlled from the terminals Fl-F3 according to Fig. 4. The device has a connection Sil for an incoming signal and a connection Sul for an outgoing signal and is adapted to secure that the outgoing signal will have a desired dying-out amplitude. The circuit shown in Fig. 6 is a known resonant circuit which is adapted at the reception of a pulse from one of the connections Fl-F3 to produce an oscillating output signal having a dying-out amplitude at the output Su2.Instead of or in addition to the circuits illustrated in Figs. 5 and 6 other circuits can of course be connected for producing as accompaniment rhythmic sound effects, bass switching, rhythmic harmony support etc.

In Fig. 7 the blocks 17 and 18 represent a device for manual rhythm switching and a rhythm generator, respectively, which can be used as alternatives on occasions where the above described rhythm control is not used.

Fig. 9 shows the circuit diagram for an electronic circuit arranged to provide levelling of the time intervals between pulses or signals in a sequence of such pulses or signals generated by means of a pedal or manually.

In the following description of the pulse stage functions it is presumed that the pedal PT, Fig. 2c, is first in the lower position and the pedal PK is first in the upper position. In Fig. 9 the contact device proper is shown in simplified manner. PN receives "earth" potential when the pedal PK is pressed down and PU is connected to earth when the pedal is released. At each actuation downwards and upwards, respectively, the state of FL15 is changed. A first actuation downward of PK renders in a 4/4-rhythm the first 16th in the first 4th and the. first actuation upwards of PK is the third 16th.

The purpose of the circuit according to Fig.

9 is independently of tempo changes as accurately as possible to place the second 16th just between the first and the third 16th and the fourth 16th just between the third and fifth 16th.

At the actuation downwards of the pedal the following is happening, it being presumed that the part I of the ring-counter, Fig. 2a, is just about to be coupled into circuit. The ring-counter is switched by connecting N to "earth", which gives +(driving)potential or voltage at Pl which in turn delivers the potential to the interconnected bases of T26-T29 in the device according to Fig. 4. When this happens T26 becomes conducting directly, and the negative pulse occurring at its collector and thus at the "horizontal" conductors of the rhythm pattern system M41 which are coupled into circuit by a diode D87--D109 and a rhythm pattern selector OKWOK6 produces the first 16th in the sound reproducing device At actuation downwards FL15 in Fig. 9 changes its state.

This means that T42 which was conducting before is blocked and the collector potential becomes almost equal to +A while the collector of T43 is set at "earth" potential.

To each collector a RC-combination is connected, to T42 the combination R141, C55, R142 is connected and to T43 the combination R146, R56, R145. As to the values of the applied components it can be said that C55 is equal to C56 and that all resistors R141, R142, R145 and R146 are equal. The capacitor C56 which was charged before actuation downwards is now discharged through R145. At the same time as this discharge starts the re-charging of C55 via R141 starts. When the voltages over C55 and C56 are equal an equilibrium is attained in which the potential in the point of connection between the diodes D122 and D123 is minimum.The discharge of C56 which partly takes place through R145 passes initially also via D123 when D122 is blocked, but as soon as said equilibrium has been reached D123 is blocked and D122 starts conducting, now with the aid of the charging potential of C55. In the state of equilibrium the current through D122 and D123 and also the base current to T44 and T46, respectively, has minimum value. This is so because the point of connection between D122 and D123 is connected via R148 and D125 or D126 to the base of the transistors T44 and T46. The base of T44 is, however, also connected to the collector of T42 via D124 and R140, and since the collector of T42 has +potential T44 is conducting and has low potential at the collector so that the Zene-diode Z6 is blocked. The base of T46 is coupled to the collector of T43 via D127 and R147. The collector is at "earth" potential. The base of T46 is therefore influenced by the potential from the point D122/D123 via R148. When the potential is at minimum, i.e. when the state of equilibrium exists, the collector of T46 has maximum potential and the Zenerdiode Z7 is chosen such that it opens at this maximum potential at the collector. The potential is transmitted via R155 to T47 which becomes conducting so that the relay Re4 is actuated. At the release of the pedal (to the position Pu) the same thing occurs but in the opposite sense with Z7 blocked and the relay Re3 operating. If the tempo is now increased, i.e. the speed between the positions PM and PU, the state of equilibrium is reached faster.The RCcombination R141, C55, R142 and R146, C56, C145, respectively, is chosen such that at the lowest exising tempo the charging and discharging of the condenser C55 is almost maximum. When the tempo is increased the potential over C55 and C56 will therefore not decrease to zero, but this is of no importance, since it is only the minimum value at the state of equilibrium which is of interest.

Thus, Re4 is actuated after actuation downwards of the pedal contact to PN so that the point RN is connected to "earth".

According to Fig. 4 the point RN is connected to the emitter of the other transistor T27 which thus will become conducting and in the collector a negative pulse occurs which thus occurs also at the "vertical" conductor in the rhythm pattern M31 corresponding to the transistor T27.

This pulse represents the second 16th and becomes perceptible in the sound reproducing device if the chosen rhythm pattern has a diode connection between this vertical conductor and the "horizontal" conductor corresponding to the rhythm pattern, which, however, is not the case in any of the examples of rhythm patterns shown in Fig. 4. At the lifting of the pedal according to Fig. 9 to PU T28 is connected to "earth" according to Fig. 4 and the pulse at the collector which thereby occurs constitutes the third 16th. A short moment thereafter Re3 according to Fig. 9 is actuated and the emitter of T29 is connected to "earth" via point RU, which is connected to "earth", and the pulse thereby occurring in the collector constituting the fourth 16th.At the next actuation downwards the ring-counter according to Fig. 2a changes over to P2 and the same process starts with the second group of four transistor circuits. According to Fig. 4, the first actuation downwards of the pedal giving the fifth 16th and the first actuation upwards renders the sixth 16th, etc.

It is apparent from the above description that the circuit according to Fig. 9 secures that the beats which are to fall between beats corresponding to a downward and upward pedal movement always will fall just between the two latter beats. If a device according to Fig. 9 is not used the rhythm pulses would come irregularly, since it is often difficult for the player, especially if he is unskilled, to succeed in having the pulses corresponding to the lifting of a pedal contact to occur at the right moment, i.e.

just between two adjacent pulses corresponding to a downward movement of the pedal, it being usually easier to get the latter pulses to occur at the right moments.

However, it should be pointed out that the rhythm pattern system can be used without any circuit according to Fig. 9 which latter should be regarded as the solution of a special problem. This problem exists also in other fields than electrical musical instruments when it is the question of producing a pulse series having even pulse intervals starting from a pulse series produced, for instance, manually and having or being liable to have uneven pulse intervals.

Fig. 8 shows a variation of the combination of resistance contact means shown in Fig. 2b which variation is used to vary certain bass notes upwards or downwards by a half tone. According to Fig.

8 four resistances and three contact means have been used to vary the third and the fifth of a bass note pattern.

As to the practical realization of an instrument it should be pointed out that this does not offer any difficulties to an expert in the electronic field, since only known standard circuit components are used. The harmony, bass and/or rhythm pattern circuits M1--M41 can suitably be formed as so called printed circuits and these can, if desired, be arranged to be easily exchangeable for instance by the use of connectors of the plug-in type. Also other units can in a similar manner be made easily exchangeable or replaceable. In this manner various types of instruments can easily be produced and in addition thereto the maintenance work can be simplified and made less expensive. British Patent Application No. 7,909,177 has been divided from this application (1564823).

List of Component 0 12=IC-circuits ITT/TCA 430 FDl2=IC-circuits ITT/SAJ 110 D l-D 201=1N4148 TR,Trl,TR2=BC 168 B Z I =BZY88/CSV6 Z2-Z5=BZY88/C9V 1 Rel,Re2=Relay 12V Rl=2,2 kohm R2=18 kohm R3=100 kohm R4=1 kohm R5=1 Mohm R6=220 kohm R7a, R7b=1Mohm R8a, R8b=33 kohm-68 kohm R9a, R9b, R9c=l5 kohm R10=220 kohm, trim R1l=220 kohm trim R12=18 kohm R13=100 kohm R14=1 kohm R15=100 kohm R16=3,3 kohm R17=22 kohm R18=22 kohm R19=3,3 kohm R20=22 kohm R21=22 kohm R22=100 kohm R23=100 kohm R25=680 kohm R26=470 kohm R27=500 kohm, trim R28=680 kohm R29=220 kohm R30=500 kohm, trim R31=100 kohm, trim R32=100 kohm, trim R33=120 kohm R34=120 kohm R35=120 kohm R36=4,7 kohm R37=15 kohm R38=4,7 kohm R39=2,2 kohm R40=1 kohm R41=2,2 kohm R42=2,2 kohm R43=1 kohm R44=2,2 kohm R45=22 kohm R46=22 kohm R47=22 kohm R48=22 kohm R49=22 kohm R50=22 kohm R51=22 kohm R52=22 kohm R53=220 kohm, trim R54=220 kohm R55=2,2 Mohm R56=470 kohm R57=470 kohm R58=470 kohm R59=100 kohm R60=470 ohm R61-R86=50 kohm, trim R87=10 kohm R88=470 kohm R89=100 kohm R90=5,6 kohm R91=470 ohm R92=680 ohm R93=2,2 kohm R94=2,2 kohm R95=500 ohm, trim R96=100 ohm, trim R97=680 ohm, R98=10 kohm R99=22 kohm R100-R115=390 kohm R116--R131=3,3 kohm R132--R135=820 kohm R136-R139=100 kohm R140--R163=100 kohm R164=470 kohm R165=10 kohm R166=1 Mohm R167=220 kohm, trim R168=100 kohm, R169=68 kohm R170=47 kohm, trim Cm=0,947 pF C2a=0,047 pF C2b=0,047 yF C3a=0,047 yF C3b=0,047 yF C3c=0,047 yF C4=0,047 yF C5=10 yF, el . lyt C6=0,l pF R23=100 kohm R25=680 kohm R26=470 kohm R27=500 kohm, trim R28=680 kohm R29=220 kohm R30=500 kohm, trim R31=100 kohm, trim R32=100 kohm, trim R33=120 kohm R34=120 kohm R35=120 kohm R36=4,7 kohm R37=15 kohm R38=4,7 kohm R39=2,2 kohm R40=1 kohm R41=2,2 kohm R42=2,2 kohm R43=1 kohm R44=2,2 kohm R45=22 kohm R46=22 kohm R47=22 kohm R48=22 kohm R49=22 kohm R50=22 kohm R51=22 kohm R52=22 kohm R53=220 kohm, trim R54=220 kohm R55=2,2 Mohm -R56=470 kohm R57=10 kohm R58=470 kohm R59=100 kohm R60=470 ohm .R86=50 kohm, trim R87=10 kohm R88=470 kohm

Claims (9)

WHAT WE CLAIM IS:

1. An electrical musical instrument having means for generating electrical signals corresponding to musical notes and members adapted to select certain of the signals for further treatment and/or for transmission to sound reproducing apparatus, characterised by a circuit responsive to operation of a single contact to cause a sequence of at least four notes in the scale of a certain key to be played automatically one after the other.

2. A musical instrument according to Claim I in which the sequence of notes comprises the fundamental, the fifth, the third, the second and the fourth of the scale of notes of the said key.

3. A musical instrument according to Claim I or Claim 2 in which if the contact is operated eight times, the fundamental, the third and the fifth occur at the Ist, the 3rd, and the 5th respectively, operations.

4. A musical instrument according to any preceding claims including a manually operable member for modifying at least one note of said sequence of notes by a half tone upwards or downwards.

5. A musical instrument according to Claim 4 in which there is such a manually operable member for modifying the third, and/or the fifth and/or the sixth of the scale of the certain key.

6. A musical instrument according to any of Claims 1--5, including a circuit which comprises a first system of conductors, each connected to one of a number of inputs to a bass note generator corresponding to a number of bass notes, and a second system of conductors connectable to conductors of the first system according to a predetermined but optional system, a ringcounter comprising a number of flip-flop circuits controllable by the player and arranged to connect a number of conductors of said second system of conductors one after the other to corresponding conductors of the first system for initiating the corresponding bass notes of the bass note generator.

7. A musical instrument according to Claim 6, in which the first system of conductors is subdivided into a number of groups of conductors each of the conductors of the second system of conductors being connectable to a conductor in each of said groups of conductors of the first system, bass note selectors operable by the player being provided to secure that only one optional group of said groups is operating at a time for controlling the bass note oscillator.

8. A musical instrument according to any preceding Claim including key selecting means, operable by the player, for selecting the certain key.

9. An electrical musical instrument arranged substantially as herein specifically described with reference to the accompanying drawings.