US1181486A - Art of producing musical tones. - Google Patents

Description

M. L. SEVERY & G. B. SINCLAIR.

ART OF PRODUCING MUSICAL TONES.

APPLICATION FILED IAN. I0. I9I0.

Patented May 2, 1916.

3 SIIEETSSHEET I.

M. L. SEVERY & G. B. SINCLAIR.

ART OF PRODUCING MUSICAL TONES.

APPLICATION FILED JAN. 10. 1910.

1,181 ,486. Patented May 2,1916.

3 SHEETS-SHEET 2.

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Geo rye B. Sindaw /%M M. L. SEVERY & G. B. SINCLAIR.

ART OF PRODUCING MUSICAL TONES. APPLICATION FILED JAN.10.1910.

1, 181 ,486. Patented May 2,1916.

3 SHEETS-SHEET 3.

vvifiqesses; IH'VEWQ/X'SJ I I :Af6l17inL.S617 y Q 25.5 v emge In M) UNITED STATES PATENT OFFICE.

MELVIN SEVERY, OF ARLINGTON HEIGHTS, AND GEORGE B. SINCLAIR, OF MEDFORD,

MASSACHUSETTS; ASSIGNORS TO CHORALCELO COMPANY, OF BOSTON, MASSACHU- SETTS, CORPORATION OF MAINE.

v ART OF PRODUCING MUSICAL TONES.

Specification of Letters Patent.

' Patented May 2, 1916.

Application filed January 10, 1910. Serial No. 537,257.

To all whom it may concern Be it known that we, MELVIN L. SEVERY, of Arlington Heights, and GEORGE B. SIN- CLAIR, of Medford, each in the county of Middlesex and Commonwealth of Massachusetts, both citizens of the United States, have invented new and useful Improvements in the Art of Producing Musical Tones, of which the following is a specification. I

The object of this invention is the educing of composite musical tones from tuned sonorous bodies, such as piano strings and the like, in order that the same sonorous body may at will be caused to emit a plurality of widely differing tone-qualities or timbres.

By means of our method or art, we are enabled to cause the sonorous bodies of a musical instrument to sound like a pipe organ, a violin, a flute, and other well known instruments, either singly or combined, at the pleasure of the operator.

In the following description and in the claims, the word tone is used as meaning sound, in relation to volume, quality and pitch; or as meaning a sound that maybe.

employed in music, having a definite pitch,

and due to vibration of a' sounding body. I

As most tones are composite, consisting of several relatively simple constituents called partial tones, of which the lowest is usually the most prominent and is hence called the principal or fundamental tone, while the others are called accessory tones, overtonesor harmonics, it becomes necessary at points in the description and claims further to define or qualify the word tone by reference to the timbre, quality or peculiar characteristic sound produced. The term tone is thus used in preference to note for the reason that, according to accepted definitions of recognized dictionaries, such as the Standard, the Century and W ebsters, tone properly pertains to thesound itself with its variations in pitch. loudness and timbre or quality, whereas note is more appropriately applied to the sign or symbol indicating or representing a given tone or sound, though as stated by these several authorities, the terms are loosely but incorrectly used interchangeably.

Referring to the drawings forming part of this specification: Figure 1 is a perspective diagrammatic View of apparatus by means of which we are enabled to carry out our method or art; Fig. 2 is a diagram in plan view of our apparatus for the production of the desired musical tones from a single set of sonorous bodies, here repre sented as vibrating strings; Fig. 3 is a side sectional elevation of apparatus for the production of composite tones by a single sonorous body; and Fig. 4 is a view of our preferred form of action brush and contact.

It has long been well known that musical sounds can be produced by throwing into vibration any tuned sonorous body,.and that such vibration may be eiiected percussion, by friction, by electromagnetic attraction, and in other ways, and where such bodies are not of material capable of direct magnetic attraction, they have been provided with armatures of soft iron, steel, or other magnetically attractable substance, as proposed, for instance, in the patent to Ohmart, No. 472,079, dated March 29, 1892. It is hence to be understood that the vibrating string here represented is merely used as a type or illustration, and that any tuned sonorous body is comprehended within our invention. and may be employed in lieu of the stretched string.

The first steps of our method or art, whereby we produce a plurality of different sonorous vibrations in a single body, are most clearly illustrated by the apparatus set forth in Fig. 3. Here the sonorous body selected is a stretched string 1, either of magnetically attractable material, or rendered capable of magnetic attraction in any common and usual way and arranged within the field of attraction of an electromagnet or magnets 2, in circuit-with a source of electric energy, the current from which is delivered in a series of pulsations. These magnetic pulsations are engendered in said magnet by a pulsation device comprising the peripherally interrupted disk 3,-rotated at constant and proper speed in contact with a brush 4, introduced in the circuit between a current-source 5 and said electromagnets 2. Such circuit in operation consists of a lead wire 6, brush 7, disk 3, brush 4, and wire 8, to said electromagnet 2; and from the latter, of wires 9, 10, contact 11, brush 12 and wire 13 back to the source The last-named brush is moved into touch with said contact and the circuit thereby completed. by means of a key ll acting through the post 15 aml lever 10.

By having the speed of the disk 3 and the number of its peripheral interruptions proportioned to accurately time such current interruptions to the normal vibrations of.

the tuned string 1, the latter will be electromagnetieally sounded with its maximum loudness and purity of tone. If, now, we rotate the disk 3 with just double its former speed, the magnetic pulsations communicated to the electromagnet 2 and the number of vibrations imparted to the string 1, will cause the latter to emit a note an octave higher but of an entirely different timbre orquality. So, also, if certain other frequencies of pulsations are impressed upon the magnet. imparting corresponding vibrations to the string, it will yield tones of different pitches and qualities. If in addition to such electromagnetically produced vibration, the string be percussively actuated by means of the hammer 20 operated by the key 14. a still richer tone will be produced, the strongly marked fundamental of the string combining with the tones electrically maintained, and giving a result of marvelous effect. Moreover, by having all the strings of the instrument similarly controlled. the effect of a plurality of simultaneously played musical instruments is produced.

lVe have further discovered that a plurality of different frequencies can be simultaneously transmitted to the electromagnet 2, and the string made to vibrate accordingly and emit a tone of correspondingly different timbre or quality.

This may be done by providing one or more additional disks 3 with differently spaced peripheral interruptions, each with its brush 4 wired to or in circuit with the electromagnet 2. The wire 8 being provided with a variable resistance 8", the intensities of the different pulsations can be varied at will and the resultant tone cduced from the string equally changed. certain harmonics being made prominent and others subdued. It is obvious. of course. that the wire 8 might similarly be provided with a resistance. though we have omitted it in the drawings for the sake of simplicity. t uch electromagnetic resultants can be impressed upon or caused to vibrate the strings either in conjunction with the percussiveaction of the hammers, or without the same, according to the desire of the player. In withdrawing the hammers from operative relation to the strings in order that the depression of the keys 14 may control only the electric actuations, it

I is only necessary to give a partial turn to the rockshaft-Ql, and thereby withdraw the upper end of the post or striker 15 from ongagement with the member 22 of the action.

Each brush 1?. as shown more clearly in Fig. 4-. is preferably formed with contact points of unequal length, and is caused to traverse two contacts 11 and 11, the latter of which is joined directly to the wires 10 and 9. but the first of which is connected with the wire 9 through a resistance 2 The purpose of this is to vary at will the current to the magnet 2, and to reduce the sparking which would otherwise occur as the brushes lea ve the contacts ll and 11, the brushes 12 being so constructed as to contact with 11 before leaving contacts 11. To withdraw the individual dampers 25 from the strings 1 both when the same are percussivcly and when they are elcctromagnctically vibrated. each damper has pivotally mounted beneath its tail a lever-arm 26 carrying a spoon 27 engaging such tail. This lever arm is depressed either by the swinging of said member 22 when the hammer associated therewith is operated. or by the downward movement of the armature 28 joined to said lever 26 by a link 99. as such armature responds to the electromagnet 30 fixed beneath it. This electromagnet is energized simultaneously with the energizing of the elcctromagnet 2. To accomplish this. each magnet'ilf) has one end of its coil connected with the wire 6 by a wire or conductor ill. which may be common to the several magnets. The opposite end of the coil or windingof each of said magnets 30 is connected to the wire 10 by an individual wire 32, or is directly connected with the contact 11 associated with the string 1 Whose damper said magnet controls. The lever arms 26 being pivotally supported independently of their associated members 22, the dampers can be moved electrically even when the hammer actions are disconnected from the keys, and said members remain quiet. As also shown in Fig. 3, the brushes 4 are of an appreciable thickness, the same being indicated by the two dotted radial lines. Consequently, a conducting section or tooth 34 will remain in circuit with such brush for a space additional to its own length equal to such contacting thickness of brush. The result is, if the low resistance sections 34 exactly equal the high resistance sections 35. that the electromagnet 2 will continue to attract its string 1 after the latter has begun its recession therefrom. with the effect of retarding the movement of the string and reducing its sonorous strength as well as af fecting its tonal quality. To obviate this retardation, our invention further consists in making the time of each energization of the electromagnet 2 preferably exactly equal to and, for best results, in any event no longer than the time of the vibrational approach of the string toward its electromagnet; the method by which we accomplish this result consisting in shortening each tooth 34 by a space at least equal to the contact-thickness of the brush, and, of course, lengthening 'the high resistance section by an equal amount.

Fig. 9. not only shows the timbre controller, or means for switching pulsations of higher frequencies into electromagnets 2 controlling strings 1 of normally lower frequencies of vibration, but switching devices or means for putting these relatively low strings vibrated at an abnormally higher pitch. into the control of keys normally associated with such higher vibrations. The brushes of the disks 3 are shown as joined by wircs 8 to the first row of a plurality of rows of contacts 36. Across the face of these contacts are moved the brushes 37, so that when said brushes are in touch with said first row of contacts. the pulsations of each disk 3 are communicated to the electromagnets 2 directly in line with the same, the wires 8 joining said brushes with said electromagnets. The contacts of the first row being wired (at the back of the board supporting the same. although not so shown) to contacts in the second row at a specified distance away toward the bass end of the board, and the contacts in this second row being wired to contacts in the third row at a still further specified distance toward the bass end, when the brushes 37 are removed to such second or third row of contacts, the pulsations of higher frequen- I cies will be transmitted to the electromagnets controlling the lower strings, as already described.

In the timbre controller as illustrated in Fig. 2, the brushes 37 are in touch with the third row of contacts 36, and each of these contacts is wired to a contact in the first row two octaves therefrom, or twenty-four spaces distant, the heavy black line 38 indicating such connection for a single note, and the pulsation disk selected being the disk whose rate of pulsation is that of the note (7, and to which in Fig. 2. C is applied. The brush thereby connected with the same is therefore that of the note G a heavy line 8 indicating its connection with the electromagnet 2 of a string 1 whose normal pitch is C From this electromagnet passes another heavy line 8. indicating a wire or conductor, to a brush 40. which wire. if said brush were in touch with the last row of contacts 41, would put the C pulsations under the control of the key (7 the wires 9 joining said last row of contacts to the contacts 11 swept by the brushes 12 (Fig. 3), of the keys-14c. We, however, consider in addition it objectionable, usually, to have a bass key controlling a treble note, and consequently prefer to have the latter put under the control of a key normally associated with the same pitch. This is the function of the switching devices comprising said brushes 12 and contacts 40, 41. These switching devices are much like the above described timbre controller, except that they reverse the direction of switching. The timbre controller switches the higher pulsations from the pulsation device down to the electromagnets of lower strings, and the switching devices 12, 40, 41 switch the current from the lower electromagnets up to the higher keys. This is indicated for a single note by the wire represented by heavy line 42. which is seen to connect the brush of the C string and electromagnet to the wire indicated by heavy line 9 joined to the con tact 11 of the key In other words, the pulsations are delivered to the C electromagnet and string. but are placed under the control of the C key. Hence by the use of both the timbre controller and the switching devices 12. 410, 41, the pitches of the notes controlled by the keys are apparently not changed but simply the timbre thereof.

' Fig. 1 illustrates the apparatus by which our complete method or art of producing tones is carried into effect. Here the parts set forth in Fig. 2 comprise the left-hand section of the figure, or the back instrument as we term the same, the part of the apparatus in the vicinity of the key board being called the front instrument, but both parts being preferably combined within a single case. Referring now to Fig. 1. in addition to what has been already described are rheostats 45 introduced into the circuits between the pulsation device brushes and the timbre controller of both the front and back instruments. Each rheostat a5 is provided with a plurality of degrees of resistance connected with the different contacts 46 over which its associated brush 47 is adapted to be swept. When such brushes are brought toward the row of contacts to which the wires 8 are joined, such resistance is more and more out out until such row is actually reached, 49 indicating such resistance-units. lVe have discovered, however, that the proportioning of such resistanceunits is no easy matter; that it does not follow that because a certain increment of resistance added to one circuit will reduce the loudness of a note a specified degree. an equal increment will equally reduce an adjoining note, nor that double such increment will make the same note one-half as loud.

We have in fact been obliged to work out the problem for each note of the entire instrument, giving each the several different degrees of loudness Which we desired such note to have, until we have eventually succeeded in plotting a series of curves representing the relative intensities of the notes, there being a separate curve for each degree of loudness.

While the rheostats are useful inmodulating the loudness of music produced by the instrument as a whole, they are as or perhaps more valuable in varying the quality of tones emitted. \Vhen the-front and back instruments are being simultaneously played,as they are adapted to be by the single bank of keys 14,-and through the suitable shifting of the timbre controller the two instruments are made to produce tones, those of one instrument differing very materially from those of the other in timbre or quality, the resultant effects can be changed by varying the adjustment of the rheostats of one or both instruments, so that one timbre shall be subdued and the other more pronounced and dominant. This will give a quite different effect from that produced when both are of equal loudness, and permits of asystem of permutations resulting in a great range of tone color. It is evident that with the hammers striking the front strings and thus eliciting their fundamental tones, the front electromagnets drawing from said strings certain tone qualities, and the rear electromagnets vibrating the rear strings differently still and causing them to give forth yet other tone qualities, the resultant music produced through the depression of keys of a single bank will equal and even surpass that of an orchestra. If it be desired to play the front instrument alone, it is only necessary to entirely withdraw the brushes 40 from the contacts 41,

and thus to cut off all flow of current to the back instrument. To withdraw the dampers from the back strings, their electromagnets 30 are joined by wires 32 to the wires 9 leading from the brush contacts 11, while a common wire 31 joins them to the source 5. From the other pole of source 5 a wire 13 and brush 12 complete the circuit to contacts 11. r

The term set as herein applied to strings, notes, sonorous bodies, and the like, refers only to a plurality of bodies having different pitches tuned in scale-relations to each other, and does not refer to that plurality of sonorous bodies tuned to the same pitch, commonly called unisons. The term sets of pulsations also used herein, is meant to express pulsations of different frequencies imposed upon or delivered to one and the same electromagnet.

From the foregoing description taken in connection with the drawings it will be seen that a given sonorous body, string or other, can under this construction and arrangement be simultaneously vibrated in three ways: by the hammer blow through the depression of the key; electrically, through the depression of the key with the circuit closer completing the circuit of the magnet for that key and its interrupter disk rotating; by the use of the timbre controller and depression of another key, which through said controller is caused to bring into circuit with the electromagnet associated with such sonorous body 'another interrupter producing a greater number of interruptions and consequent pulsations, and hence giving a greater number of vibrations. If, therefore, these three modes be employed simultaneously there will be produced from the same string or sonorous body three sets of vibrations, andas a consequence a tone incident to the hammer blow, that is to say, a tone having the pitch for which the body is tuned and the overtones and quality incident to such hammer blow; there will also be educed a tone incident to the electrical vibration of the body at the same rate as is occasioned by the hammer blow, but giving the even and sustained tone incident to perfect uniformity and constancy of vibration; and there will be, lastly, a similarly uniform and constant vibration of the body at a frequency greater than that occasioned by either the hammer blow or the pulsations produced by the interrupter normally associated" with such body, that is to say, there will be superimposed upon the other vibrations of said sonorous body a set of vibrations incident to bringing into electric circuit with it an interrupter producing a frequency of pulsation greater than that produced by the interrupter normally assoeiated with the magnet of such body.

A single set of vibrations may be imparted to the sonorous body by the hammer blow or electrically; or it may be vibrated by the hammer blow and simultaneously electrically vibrated at the same frequency;

or it may be vibrated by the hammer blow at the frequency which produces the fundamental tone for which such body is tuned, and simultaneously vibrated electrically at a greater frequency; or it may be simultaneously vibrated at two different frequencies through the electrical pulsations produced in the electromagnet associated with such body. Finally, the three sets of vibrations may be simultaneously produced. It is in this sense that the expression sets of pulsations is employed in the following claims.

From the fact that the individual tones, and the distinctive tone qualities incident to each different set of vibrations, are clearly present and distinguishable when the several sets of vibrations are impressed upon the sonorous body, it is evident that each set preserves its identity notwithstanding the presence of the others. The resultant vibration is apparently a compound or complex vibration, and the several tones .with their peculiar tone qualities, blend more or. less with and modify each other, or produce a composite tone efiect, but each separate tone is nevertheless distinguishable and in itself apparently unchanged by the presence of the others.

The term vibrating freely is here used as meaning vibrating at the rate or with the fre'quencynatural or normal to the given string or sonorous body, or in other words is intended to differentiate such vibration from a forced or abnormal vibration.

As prolongation of the electrical impulse and consequent magnetic action in producing a swing or movement of the vibrating body beyond the time required to complete such swing, is found to interfere with or destroy the perfect sound effect sought, it is to be understood that while such impulse should equal in duration the time required for such swing or movement of the vibrating body, it should not exceed that time. The claims are hence to be read with this understanding, and where expressions such as impulses the duration of each of which is made to equal the time consumed by said sonorous body in its vibrational swing in one direction, and the like, occur, they are to be read or interpreted accordingly.

We claim 1. The art of educing musical tones, which consists in percussively vibrating a tuned sonorous body, and simultaneously subjecting the same to the attraction of an electro magnet receivin two sets of electric pulsations, one set of a frequency to educe the tone for which said body is tuned and another set of a higher frequency.

2. The art of educing musical tones from a tuned sonorous body, which consists in simultaneously delivering to an electro-mag net located in attractive relation to such body, a plurality of distinct and independent sets of electrical pulsations of different frequencies bearing a recognized musical re lation, those of one set having the frequency of the free vibrations of such tuned sonorous body.

3. The art of educing musical tones from a tuned sonorous body, which consists in simultaneously delivering to an electromagnet located in attractive relation to such .7 body a plurality of distinct and independent sets of electrical pulsations of different frequencies bearing a recognized musical relation, those of one set having the frequency of the free vibrations of such tuned sonorous body, and others having higher frequency.

4. The art of educing a variety of tone qualities from a single tuned body, which 5. The art of educing a variety of tone qualities from a single set of key-controlled tuned sonorous bodies embracing a number of octaves, which consists in producing a set of electric pulsations for each said body, corresponding in frequency to the normal vibrations thereof when producing the fundamental tone for which it is tuned; impressing pulsations of higher frequency up on a body tuned to lower pitch, thereby causing said body to vibrate at a frequency other than that which produces its fundamental tone and temporarily putting I the body of normally lower pitch under the control of the key primarily controlling the body of normally higher pitch.

6. The art of educing from a tuned body a plurality of tonal efiects simultaneously, which consists in delivering to an electro: magnet in attractive relation to said body a plurality of sets of electric pulsations of different frequencies, and selecting said frequencies by means other than the sonorous body. I

7. The art of producing musical tones,

which consists in imparting to a tuned sonorous body a series of impulses the duration of each of which is made to equal the time consumed by the said sonorous body in its vibrational swing in one direction.

8. The herein-described art of educing musical tones from magnetically attractable sonorous bodies tuned to a musical scale, which consists in simultaneously delivering to the actuating magnet of a selected one of said bodies a plurality of sets of electric pulsations, those of one set corresponding in frequency to the free vibrations of said body, and those of the other set being of higher frequency.

9. The art of educing from a tuned sonorous body varying tonal effects, which consists in delivering to an electromagnet in attractive relation to said body a plurality of sets of electric pulsations of different frequencies; selecting said frequencies by means other than the sonorous body itself; and varying the resistance to passage of current to said magnet.

10. The art of producing tonal effects from a plurality of bodies tuned to the same pitch, which consists in delivering to electro magnets each in attractive relation to its associated body, electric pulsations. those delivered to the magnet associated with one invention, We have hereunto set our hands body being of the frequency of the free vithis 6th day of January, 1910.

brations of such body, and those delivered MELVIN L. SEVERY.

to the other magnet being of a higher fre- GEORGE B. SINCLAIR. 5 quenoy than the free vibrations of said Witnesses:

bodies. A. B. UPHAM,

In testimony that we claim the foregoing EDWARD G. THOMAS.

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