US3755609A

US3755609A - Integrated circuit all-harmonic wave organ system including provision for flute tones and pedal notes

Info

Publication number: US3755609A
Application number: US00248677A
Authority: US
Inventors: D Millet; R Schrecongost
Original assignee: Hammond Corp
Current assignee: Marmon Co
Priority date: 1972-04-28
Filing date: 1972-04-28
Publication date: 1973-08-28
Anticipated expiration: 1990-08-28
Also published as: GB1405238A; AU5235873A; BR7303087D0; NL7302619A; IT981725B; JPS5391822U; CA966706A; ZA731092B; JPS4923621A; DE2318881A1; JPS5933040Y2

Abstract

A bright wave (all harmonic wave) organ system which has direct current (D.C.) keying for all notes, both manual and pedal, and also provides sine wave (flute) notes by filtration. All-harmonic waves are provided by stairstepping octavely related square waves and the flutes by filtration of the complex stairstepped wave minus the square wave component which has its fundamental at twice the frequency of the desired flute note to accommodate octave flute filtering. The present arrangement is such that one integrated circuit package provides for two octavely related groups of adjacent notes, all C''s and all C ''s, for instance, for eight octaves of manual notes and three octaves of 16-, 8- and 4foot pedal notes or the equivalent. Each circuit package requires only one musical frequency input or clock for each of two adjacent note groups, one for C and one for C for instance. The integrated circuit packages are large scale integrations (LSI) and include the frequency dividers, the arrangement for keying and stairstepping the square waves, for collecting and controlling the outputs for octave or half octave sine wave filtration and for formanting, and for providing three pedal outputs, one each for the 16-foot, 8-foot and 4-foot pedal notes or the equivalent for other use. Provision is made for phase synchronization of the frequency dividers.

Description

United States Patent [1 1 Millet et a1.

[ Aug. 28, 1973 1 INTEGRATED CIRCUIT ALL-I-IARMONIC WAVE ORGAN SYSTEM INCLUDING PROVISION FOR FLUTE TONES AND PEDAL NOTES [75] Inventors: David Millet, Cambridge, Mass.; Ray

B. Schrecongost, Park Ridge, 111.

[73] Assignee: Hammond Corporation, Deerfield,

[22] Filed: Apr. 28, 1972 [21] Appl. No.: 248,677

84/DIG. 11; 307/227, 260, 261, 303, 304;

[56] References Cited UNITED STATES PATENTS 3,353,104 11/1967 Loposer 307/227 X 3,430,073 2/1969 Leonard 307/260 3,628,061 12/1971 Jackman.... 307/227 X 3,654,558 4/1972 Tomisawa.. 307/227 X 3,714,461 1/1973 Dodson 307/227 3,499,090 3/1970 Meyer 84/1.0l 3,505,461 4/1970 Omura et a1... 84/1.01 3,515,039 6/1970 Omura et a1... 84/l.01 3,520,892 7/1970 Malmfors 84/l.01 3,534,144 10/1970 Ring 84/1.01 3,535,429 10/1970 Uchiyama... 84/1.01 3,590,131 6/1971 Reyers 84/1.0l X 3,626,076 12/1971 Uchiyama 8411.23

I 4166; C aocK a 100 CHE/9R B 1 1% ArmrneyWil1iam F. Gradolph et a1.

[5 7] ABSTRACT A bright wave (all harmonic wave) organ system which has direct current (D.C.) keying for all notes, both manual and pedal, andalso provides sine wave (flute) notes by filtration. All-harmonic waves are provided by stairstepping octavely related square waves and the flutes by filtration of the complex stairstepped wave minus the square wave component which has its fundamental at twice the frequency of the desired flute note to accommodate octave flute filtering. The present arrangement is such that one integrated circuit package provides for two octavely related groups of adjacent notes, all Us and all C s, for instance, for eight octaves of manual notes and three octaves of 16-, 8- and 4-foot pedal notes or the equivalent. Each circuit package requires only one musical frequency input or clock for each of two adjacent note groups, one for C and one for C for instance. The integrated circuit packages are large scale integrations (LS1) and include the frequency dividers, the arrangement for keying and stairstepping the square waves, for collecting and controlling the outputs for octave or half octave sine wave filtration and for formanting, and for providing three pedal outputs, one each for the 16-foot, 8-foot and 4- foot pedal notes or the equivalent for other use. Provision is made for phase synchronization of the frequency dividers 14 Claims, 4 Drawing Figures INTEGRATED CIRCUIT ALL-HARMONIC WAVE ORGAN SYSTEM INCLUDING PROVISION FOR FLUTE TONES AND PEDAL NOTES FIELD OF THE INVENTION This invention is primarily concerned with the efficient adaptation of metal oxide silicon field effect transistor (MOSFET) integrated circuit techniques to the provision of large scale integration (LSI) for a bright wave (all-harmonic wave) organ system including provision for flute tones (sine waves). The system also provides 16-foot, 8-foot and 4-foot pedal notes of bright wave type. The system is such that each circuit package (all are identical) provides for octavely related groups of two adjacent notes, such that six packages provide all the notes required for a manual of keys including those needed for the pedal keys. Provision is made in the LSI packages for keying, stairstepping, frequency division and output mixing, so that the only signal inputs required are two clocks, one for each of the adjacent note octave groups. The outputs are mixed such that the number of package pins or terminals are minimized. A novel scheme is also provided to permit filtration of the outputs from several packages in octave groups to obtain sine waves in spite of the fact that the system is basically of all-harmonic wave type. The system can be used to provide all the notes of an organ, and for convenience will be largely so described, but probably has its greatest utility in expanding the resources of an organ which also has other note sources of a different character.

SUMMARY OF THE INVENTION Bright wave organs, referred to also as all-harmonic wave organs or formant organs are based upon the principle that by starting with all-harmonic waves, which include the fundamental and a generally declining series of both even and odd harmonics, this wave can be formanted (filtered and resonated) to give a wide variety of tonal characteristics. All-harmonic waves of the most useful type to provide a starting point are of the sawtooth variety. That is, they can be expressed as having a substantially instantaneous rise time and a straight line decay or the reverse.

One way of providing all harmonic waves is to start with square waves, which include only the fundamental and a declining series of odd harmonics, and to add an octavely related series in a manner commonly known as stairstepping. Thus, to a square wave at the frequency of the fundamental is added the square wave an octave higher at half the voltage level, plus the square wave two octaves higher at one-fourth the level, plus the square wave three octaves higher at one-eighth the voltage level. Addition of four such octavely related square waves produces a wave having a succession of small stair steps which closely approximates a true sawtooth. This stair step wave can be formanted to produce a number of useful musical responses, but does not lend itself to octave-wide filtration for the production of sine waves required for flute tones. This is because any sine filter must pass the fundamental but discriminate against the second and all higher harmonics. The number of notes that can be filtered together is, therefore, strictly limited and so a large number of rather expensive filters is required.

The usual approach is to filter the square wave to remove everything but the fundamental rather than to start with the all-harmonic wave, since in a square wave the closest harmonic to the fundamental is three times the frequency of the fundamental and thus, each filter can accommodate approximately an octave of tone signals which cover a range of only two to one.

It is customary to obtain all-harmonic waves by stairstepping square waves and the most convenient arrangement for providing the tone signals at all the note frequencies required by the instrument is to provide 12 master frequencies or clocks for the top octave of the instrument and to divide each of these by two to obtain the next octave lower and so on. The most reliable and generally preferred circuit for such binary division, particularly when identical circuits are to be used at widely different frequencies, is the flip-flop which has a square wave output. It is thus an advantage to make use of the resulting square waves which are present at all the various frequencies as the starting point for the allharmonic or bright waves.

A problem which, therefore, arises, if an LSI is used for frequency division and mixing for stairstepping, together with keying, all in a single package, is to get another set of leads out of the package from the square wave sources for sine wave filtration without overloading the pin or terminal capacity of the package. The present invention, among other things, solves this problem by making separate output terminals for square wave note signals unnecessary and accomplishes this by the provision of only one extra terminal over what is required if the package is to supply stairstepped waves only.

Certain features of the present disclosure are also present in US. Pat. No. 3,636,231, which issued Jan. 18, I972, in the names of Ray B. Schrecongost and David Millet, entitled D. C. KEYED SYNTHESIS ORGAN EMPLOYING AN INTEGRATED CIRCUIT.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I, composed of FIGS. IA and 1B is a diagrammatic representation of a large scale integration (LSI) for carrying out the present invention for two groups of adjacent octavely related notes, specifically in the present example, the C and C notes;

FIG. 2 is a diagrammatic representation of a complex wave keyer forming a portion of FIG. I for synthesizing stair step waves from square wave sources; and

FIG. 3 is a diagrammatic representation of the complex wave keyer system used in FIG. 1 for supplying a group of 16 feet, 8 feet and 4 feet pedal notes or their equivalent.

DESCRIPTION OF THE PREFERRED EMBODIMENT In this description and in the drawing the terminology and the symbols conform to that which appears to be customary in the large scale integrated circuit (LSI) industry. Circuit arrangements on the LSI chips for accomplishing well known purposes are not shown nor described in detail. Such detail is not necessary to an understanding of the invention and would unnecessarily complicate and enlarge the disclosure. Commonly used circuit elements such as flip-flop frequency dividers which divide by two, buffers which compensate for signal level variation, clearing circuits for resetting the flip-flops to zero or some other starting position when a pulse is applied to a lead connected to the flip-flops,

gate circuits which open or close, depending upon the potential applied to a lead, and such are simply described in terms of the function they perform. Interconnections between such elements are, however, shown and described.

The system uses LSI packages, all of which are identical and each of which is connected to supply two groups of octavely related notes a semitone apart. To be specific, the package to be described in detail is connected to supply all of the C and C notes. Another will supply the D-and D notes and another the E and F notes, and so on. Each package supplies eight octaves of these notes, from C to C and C 1 to C for example, and also supplies three octaves of 16 feet, and 8 feet and 4 feet pedal notes or the equivalent for both C and C extending upwardly from the 16 feet C note with its fundamental at C Although these are referred to here as pedal notes they may, of course, be connected to have other uses. The distinguishing characteristic is that they have separate package output terminals for the 16 feet, the 8 feet and 4 feet notes.

As shown in FIG. 1, the C note system occupies the left side of the figure and the C system the right side. Since the circuits are identical, excepting for certain portions in common, only the circuit relating to the C notes will be described in detail.

At the top of FIG. 1, a terminal at 100 is connected to a C-clock which is external to the package. This C- clock supplies an input signal at 4186 Hz, C

Terminal 100 is connected through a buffer stage 102 to lead 104 connected in turn to binary frequency divider flip-flop 106. The output 108 of divider 106 is connected to a second divider 110. Its output 112 is connected to a third divider 114. This divider cascade is continued with the successive additional stages indicated respectively by the

numerals

118, 122, 126 and 130, and the interstage leads by the numerals 1 16, 120, 124 and 128. The output from the last stage 130 has the numeral 132. The frequencies, using musical designation, available on the several leads, therefore, are: lead 104, C 108, C ;112, C 116, C 120, C 124, C 128, C and 132, C,. All of these note frequencies are square waves and have approximately equal peak voltages. The buffer at 102 compensates for possible voltage variation of the C-clock relative to the outputs of the frequency dividers.

A terminal 134 is connected through a buffer 136 to line 138 which is connected in turn to each of the

frequency dividers

106, 110, 114, 118, 122, 126 and 130. This is a clearing system and operates to reset all of the frequency dividers to a uniform starting position whenever a pulse of proper polarity is applied to terminal 134. If the present system alone were to be relied upon for supplying all of the notes of an organ, this clearing system would not be needed. Since, however, the organ may have other sources for the same note, it is necessary that the C notes, as an example, for all sources be in phase so as to prevent cancellation effects. Therefore, some source, one of the C note sources, for example, in another part of the system not described here, is arranged to supply a periodic pulse, conveniently at half the frequency of the lowest musical note to terminal 134, which resets all of the C note systems to uniform starting positions. The C notes, therefore, from whatever sources are in phase. Once in phase they usually remain in phase. The synchronizing system ordinarily is thus called upon to reset the frequency dividers to a zero starting position only when the instrument is turned on. The same system is, of course, used to insure synchronization of the other notes.

Those particularly interested in this feature are re ferred to the copending US. Pat. application of Ray B. Schrecongost, Ser. No. 184,810, filed Sept. 29, 1971 entitled INTEGRATED CIRCUIT SYNTHESIS AND BRIGHT WAVE ORGAN SYSTEM and assigned to the assignee of the present application, where this feature is discussed in greater detail.

Below the frequency dividing cascade just described is a group of eight keying blocks 140. These blocks are identical and one is shown in greater detail in FIG. 2. They are distinguished from each other by the note each keys or plays whenever actuated. The blocks 140, therefore, carry the additional individual designations beginning at the left of C C C C C C C, and C,,, respectively.

Referring to FIG. 2, the keying block 140 has a minus l4-volt Vdd lead 142 connected to the drains of four low resistance MOSFET elements 144, 146, 148 and 150. The gates of these elements have leads labeled F (fundamental), 2F (twice the fundamental), 4F (four times the fundamental) and SF (eight times the fundamental). The source of MOSFET 144 is connected to the drain of another MOSFET element 152 and its source to a keyer output lead 154. Each of the other elements 146, 148 and 150 is similarly connected through a medium resistance

second MOSFET

156, 158 and 160, respectively, to the output 154. The gates of

elements

154, 156, 158 and 160 are connected together and to a keying terminal 162.

Externally of the LS1 package, playing key contacts 164 actuated by the appropriate playing key for the note apply an appropriate keying potential from a source 166 to the terminal 162. Any desired envelope shaper 168 may be employed to give this keying potential an appropriate envelope. It may be steady and be applied and removed by simple make and break action of the contacts 164 or it may have a sustain or a percussive envelope. Keying envelope shapers for this purpose are well understood and need no particular description here.

The keyer operates as follows. Assume that an appropriate square wave signal at the desired fundamental frequency for the note is applied to lead F, and that square waves at twice, four times, and eight times the fundamental frequency are applied respectively to leads 2F, 4F and SF. Under these conditions these square waves applied to the MOSFET gates will chop the Vdd DC. potential and apply the resulting square waves to

MOSFETs

152, 156, 158 and 160. When the playing key actuating the contacts 164 is pressed, the resulting potential with the desired envelope applied to the gates of

MOSFETs

152, 156, 158 and 160 causes these elements to become conductive and apply the mixed square wave signals to the output 154.

At the time of manufacture, the geometry of the MOSFET elements is made such that when operated the effective resistance through elements 146 and 156 in series is twice that through elements 144 and 152; that through 148 and 158 is four times 144 and 152, and that through 150 and 160 is eight times 144 and 152. The mixture of square waves is, therefore, scaled to produce a stairstep wave which approximates an allharmonic bright wave. In a typical configuration, for example, the MOSFETs 144, 146, 148 and 150 may have a resistance of 100 ohms and

MOSFETs

152, 156, 158 and 160 may have resistances respectively of 5K, K, 20K, and 40K.

C keying block 140 has its F lead connected to C,

lead 132, its 2F lead connected through a MOSFET gate 170 to C lead 128, its 4F lead connected to C lead 124 and its 8F lead connected to C lead 120. Gate 170 prevents C frequency from being applied to the keyer block 2F lead unless an appropriate potential is applied to a gate control lead 172.

All of the other keying blocks 140 for C C C C C,,, C-, and C are similarly connected. That is, in each case, the F lead is connected to receive the fundamental frequency the 2F lead to receive twice the fundamental frequency and so on, and in each case the 2F lead is connected through a gate 170 which has its control terminal connected to control line 172.

Control line 172 is in turn connected to a package terminal pin 174.

An exception will be noted in that C keyer block has no connection to its 8F lead, C keyer is likewise missing connections to its 4F and 8F leads, and C, has an input only to its F lead. At the high frequencies involved (8,372 Hz and higher) even the lowest of these missing harmonics is not sufficiently noticeable to justify the additional expense of its inclusion. To include it would require an additional frequency divider in the cascade and a clock at the 8,372 Hz frequency.

As mentioned previously, the C portion of the circuit duplicates that described above and for convenience the same numerals have been used to designate the elements, and to avoid confusion, only certain key numerals have been applied. It is sufficient to note that the C clock terminal 100 is connected to receive a C 8 frequency at 4,435 Hz. For convenience the musical note frequencies C C etc., have been noted on the leads and on the keyer blocks 140. The keyer block outputs 154 have been indicated as have the gates 170 in the 2F leads, these gates also being connected to gate control line 172 leading to terminal 174.

The several keyer outputs 154 are connected as follows. A package terminal 176 is connected to leads 154 for keyer blocks C C C and C# Terminal 178 is connected to leads 154 for keyer blocks C and C 23 Similarly, the outputs 154 for blocks C and C 23, are connected to terminal 180, those for C and C 3,, to terminal 182, those for C and C 6 to terminal 184, those for C and C 1 to terminal 186 and those for C, and C a to terminal 188.

By manifolding the outputs together within the LS1 in this manner only seven package output pins are required for the 16 notes produced. The

output terminals

176, 178, 180, 182, 184, 186 and 188 are connected along with the similar terminals for other packages which produce and key other notes to the output system of the instrument through the usual formanting cir-.

cuits and also through sine filters which have a band pass of something more than an octave. When allharmonic bright wave tones for formanting are desired, the potential applied to terminal 174 by any suitable switch controlled circuit, not shown since its provision will be obvious, connected to terminal 174 is such as to turn on or open all of the gates 170 so that the second harmonic, and the odd harmonics of the second, are included in the stairstep mixture present at the outputs 154 of the keyer blocks. On the other hand, if flute tones are desired, the potential applied to terminal 174 is such as to shut off or close all the gates 170. Under these conditions, the mixture at the keyer output termi nals 154 includes the fundamental and all the harmonics normally present in the stairstep wave excepting the second harmonic and the odd harmonics of the second. The result is that the mixed output is missing the second, sixth, 10th, etc., harmonics. The importance of this is that since the second harmonic is missing, the closest harmonic to the fundamental is the third harmonic which is present in the square wave applied to the keyer input lead F.

Although this output wave form is much more complex than the ordinary square wave, which is the wave form heretofore preferred for filtration to produce flute tones, it is no more difficult to filter because the closest frequency which needs to be removed from association with the fundamental is three times the frequency of the fundamental in both cases. By the addition of only one terminal, 174, for control of all the second harmonics, the package is made to supply both allharmonic stair-step waves for formanting, and waves which can satisfactorily be filtered in octave groupings to produce flute tones (sine waves) simply by changing the potential at the single package terminal 174. Waveform control such as described may also be useful for other tonal changes with or without filtering, by controlling other square wave components of the stair step circuit.

For this portion of the circuit, the package supplies and keys eight octaves of two adjacent notes (C and C for example) in both all-harmonic form and in a form suitable for filtration to produce flute tones with only the need for the following package terminals. Ground and two voltage terminals, known usually as Vdd and Vgg for functioning of the MOSFET circuit elements, plus two inputs for the two clocks and two clearing terminals, plus seven output terminals, the 16 terminals 162 for connection to playing key circuits, and the single terminal 174 for control of the second harmonics, for a total of only 31 package pins for 16 notes in two different wave forms. In the interest of simplifying the drawing, the Vgg or gates voltage lead is not shown connected to the circuit elements. As is typical, the Vdd or drain voltage is at about 14 v. relative to ground and the Vgg voltage is twice this, or 28 v., so that it is 14 v. relative to the drains potential. Although these values are typical, the supplier of a particular integrated circuit may suggest somewhat different values. This is extremely economical in terminal requirements, particularly when it is appreciated that 16 of the pins are required for connection to the contact systems of the 16 playing keys of the instrument served by the package.

The systems for keying and providing the 16 feet, 8 feet and 4 feet pedal notes for the two adjacent semitone groups (C and C in this example) are alike and, therefore, description of the one to the left for the C notes will suffice for both. A keying system 200, see FIG. 3, for the low C is composed of three groups of keying blocks of the type illustrated in FIG. 2, one each for the 16 feet, the 8 feet and the 4 feet note. One playing key connection 202 controls all three of these blocks so that all key together when the low C playing key is actuated. Similarly, the Vdd voltage line 142 is connected through to all three keyer blocks. The outputs for the three blocks provide separate output terminals for the 16 feet, the 8 feet and the 4 feet notes respectively at 204, 206 and 208.

Each of the three keying blocks has four music tone signal input connections F, 2F, 4F and SP for the fundamental frequency, twice the fundamental frequency, four times and eight times the fundamental frequency, respectively. These are connected as follows. C lead 132 is connected to F of the 16 feet keyer block. C lead is connected to 2F of the 16 feet block and F of the 8 feet keyer block. C is connected to 4F of the 16 feet block, 2F of the 8 feet block and F of the 4 feet block. C, is connected to SF of the 16 feet block, 4F of the 8 feet block and 2F of the 4 feet block. C is connected to 8F of the 8 feet block and 4F of the 4 feet block and C is connected to SF of the 4 feet block.

Thus, when the low C playing key is actuated, all 12 of the keyers in the three blocks pass stair step waves an octave apart to the three

outputs

204, 206 and 208 for the 16 feet, 8 feet and 4 feet all-harmonic wave notes respectively, based on C for the 16 feet note.

Another compound set of keyers for 16 feet, 8 feet and 4 feet C notes an octave higher than the group for the lowest C playing key are shown at 210 and a third set for C two octaves higher than the lowest are indicated at 212. These keyer groups are the same as those described above excepting that all note signal input leads are shifted upwardly one octave for group 210 and two octaves for group 212. The individual 16 feet, 8 feet and 4 feet outputs from each of these groups are connected to the same output 16 feet, 8 feet and 4

feet terminals

204, 206 and 208, respectively.

The same arrangement is shown on the right half of FIG. 1 for the three groups of 16 feet, ,8 feet and 4 feet C notes. The outputs for the C portion of the circuit are connected to the same terminals as the C portion of the circuit so that all of the 16 feet C and C notes in three octaves appear at the same terminal 204. Similarly, all 8 feet and all 4 notes appear at

terminals

206 and 208 respectively.

This system, therefore, adds to the package the ability to supply and key three octaves of all-harmonic wave 16 feet, 8 feet and 4 feet notes for two adjacent semitones, C and C in this specific example, and in so doing requires the addition of only nine additional package terminals, six for the C and C playing key leads and three output connections for the 16 feet, 8 feet and 4 feet outputs.

We claim:

1. A large scale integration circuit package for supplying and keying octavely related notes for an electrical musical instrument in both all-harmonic form and in a form suitable for filtration in substantially octave groups to produce flute tones comprising circuits within said package providing a binary divider chain, said package having an input to said chain for connection to receive a clock frequency, said divider chain providing a plurality of square wave signals which are successive binary submultiples of the clock frequency applied to said input, and connections to supply each of said square wave signals, a plurality of keyer groups, each of said keyer groups consisting of a plurality of individual keyers interconnected to be actuated to a conducting condition to pass a signal from each keyer input to its output when a keying potential is applied to a package terminal connected to all of the keyers of its group, each of the keyers of a group having input connections to said chain connections such that when a keying potential is applied to a group to make the keyers of said group conductive, one of said keyers in the group will conduct a square wave from said chain at the fundamental of a desired note, another will conduct the square wave from said chain at the second harmonic of said note and a third will conduct the square wave from said chain at the fourth harmonic of said note, means within the package providing a common mixed output for the keyers of each group, the effective relative resistances of the keyers of each group being scaled such that the mixed signal at the common output of the group forms a stairstep wave, gate means in the connection between the divider chain and the common output through the second harmonic keyer in each of the groups, said gate means being conductive or not depending upon the voltage applied to an element of said gate, and a terminal for said package connected to all of the last said gate elements for opening or closing all of said gates together depending upon the potential applied to the last said package terminal.

2. The circuit package as called for in claim 1 in which said gate means are in the connections between the second harmonic keyers and the divider chain.

3. The circuit package as called for in claim 1 in which the package has input clock connections, divider chains and a plurality of keyer groups for two octave groups of notes a semitone apart, and in which the keyer group outputs for notes a semitone apart are connected together internally of the package.

4. The circuit package as called for in claim 2 in which the package has input clock connections, divider chains and a plurality of keyer groups for two octave groups of notes a semitone apart, and in which the keyer group outputs for notes a semitone apart are connected together internally of the package.

5. The circuit package as called for in claim 1 in which there are additional groups of keyers in said package connected to said divider chain, the last said groups of keyers being connected to said chain to provide 4 feet, 8 feet and 16 feet stairstep note outputs for at least two octaves.

6. The circuit package as called for in claim 2 in which there are additional groups of keyers to said package connected to said divider chain, the last said groups of keyers being connected to said chain to provide 4 feet, 8 feet and 16 feet stairstep note outputs for at least two octaves.

7. The circuit package as called for in claim 3 in which there are additional groups of keyers to said package connected to said divider chains, the last said groups of keyers being connected to said chains to provide 4 feet, 8 feet and 16 feet stairstep notes for at least two octaves of two groups of notes a semitone apart, said package having 4 feet, 8 feet and 16 feet output terminals connected to be common to all the 4 feet, 8 feet and 16 feet outputs respectively.

8. A large scale integration circuit package for supplying and keying octavely related notes for an electrical musical instrument in different wave forms comprising a large scale integration package having circuits therein providing a binary divider chain, an input to said chain for connection to receive a clock frequency, said divider chain providing a plurality of square wave signals which are successive binary submultiples of the clock frequency applied to said input, and connections to supply each of said square wave signals, a plurality of keyer groups, each of said keyer groups consisting of a plurality of individual keyers interconnected to be actuated to a conducting condition to pass a signal from each keyer input to its output when a keying potential is applied to a package terminal connected to all of the keyers of its group, each of the keyers ofa group having input connections to said chain connections such that when a keying potential is applied to a group to make the keyers of said group conductive, the keyers of said group will conduct a plurality of octavely related square waves, means within the package providing a common mixed output for the keyers of each group, the effective relative impedances of the keyers of each group being scaled such that the mixed signal at the common output of the group forms a stairstep wave, gate means in the connection between the divider chain and the common output through at least one of the keyers in each of the groups, said gate means being conductive or not depending upon the voltage applied to an element of said gate, and a terminal for said package connected to all of the last said gate elements for opening or closing all of said gates together depending upon the potential applied to the last said terminal.

9. The circuit package as called for in claim 8 in which said gate means are in the connections between the keyers and the divider chain.

10. The circuit package as called for in claim 8 in which the package has input clock connections, divider chains and a plurality of keyer groups for at least two groups of notes, each of said groups comprising several octavely related notes, and in'which the keyer group outputs for at least some of the notes within the same octave are connected together internally of the package.

11. The circuit package as called for in claim 9 in which the package has input clock connections, divider chains and a plurality of keyer groups for at least two groups of notes, each of said groups comprising several octavely related notes, and in which the keyer group outputs for at least some of the notes within the same octave are connected together internally of the package.

12. The circuit package as called for in claim 8 in which there are additional groups of keyers within the package connected to said divider chain, the last said groups of keyers being connected to said chain to provide 4 feet, 8 feet and 16 feet stairstep note outputs for at least two octaves.

13. The circuit package as called for in claim 9 in which there are additional groups of keyers within the package connected to said divider chain, the last said groups of keyers being connected to said chain to provide 4 feet, 8 feet and 16 feet stairstep note outputs for at least two octaves.

14. The circuit package as called for in claim 10 in which there are additional groups of keyers within the package connected to said divider chains, the last said groups of keyers being connected to said chains to provide 4 feet, 8 feet and I6 feet stairstep notes for at least two octaves of two groups of notes a semitone apart, said package having 4 feet, 8 feet and 16 feet output terminals connected to be common to all the 4 feet, 8

feet and 16 feet outputs respectively.

Claims

8. A large scale integration circuit package for supplying and keying octavely related notes for an electrical musical instrument in different wave forms comprising a large scale integration package having circuits therein providing a binary divider chain, an input to said chain for connection to receive a clock frequency, said divider chain providing a plurality of square wave signals which are successive binary submultiples of the clock frequency applied to said input, and connections to supply each of said square wave signals, a plurality of keyer groups, each of said keyer groups consisting of a plurality of individual keyers interconnected to be actuated to a conducting condition to pass a signal from each keyer input to its output when a keying potential is applied to a package terminal connected to all of the keyers of its group, each of the keyers of a group having input connections to said chain connections such that when a keying potential is applied to a group to make the keyers of said group conductive, the keyers of said group will conduct a plurality of octavely related square waves, means within the package providing a common mixed output for the keyers of each group, the effective relative impEdances of the keyers of each group being scaled such that the mixed signal at the common output of the group forms a stairstep wave, gate means in the connection between the divider chain and the common output through at least one of the keyers in each of the groups, said gate means being conductive or not depending upon the voltage applied to an element of said gate, and a terminal for said package connected to all of the last said gate elements for opening or closing all of said gates together depending upon the potential applied to the last said terminal.

10. The circuit package as called for in claim 8 in which the package has input clock connections, divider chains and a plurality of keyer groups for at least two groups of notes, each of said groups comprising several octavely related notes, and in which the keyer group outputs for at least some of the notes within the same octave are connected together internally of the package.

14. The circuit package as called for in claim 10 in which there are additional groups of keyers within the package connected to said divider chains, the last said groups of keyers being connected to said chains to provide 4 feet, 8 feet and 16 feet stairstep notes for at least two octaves of two groups of notes a semitone apart, said package having 4 feet, 8 feet and 16 feet output terminals connected to be common to all the 4 feet, 8 feet and 16 feet outputs respectively.