US2456575A - Decatonic keyboard - Google Patents

Description

Dec. 14, 1948. L, YOUNG 2,456,575

DECATONIC KEYBOARD Filed Dec. 18, 1947 I 2 Sheets-Sheet i mam com D5514, 1948. YO 2,456,575

DECATONIG KEYBOARD Filed Dec. 18, 1947 2 Sheets-Sheet 2 Lyman lzfizy Patented Dec. 14, 1948 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a keyboard for musical instruments and more particularly to a keyboard adapted for the Equal Quartertone Temperament and the American Quartertone Temperament.

An object of this invention is to provide a keyboard for a musical instrument comprising a 24 tone octave.

Another object of this invention is to provide a keyboard comprising 24 digitals per octave.

Still another object of this invention is to provide a keyboard comprising 24 digitals per octave arranged with decatonic digitals and 14 prismatic digitals wherein the prismatic digitals are arranged as '7 upper and 7 lower digitals.

To the foregoing objects, and others which may hereinafter more fully appear, the invention consists of the novel construction, combination and arrangement of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention as claimed.

In the drawings:

Figure 1 is a fragmentary top plan view of a keyboard constructed according to an embodiment of this invention,

Figure 2 is a front elevation of the keyboard shown in Figure 1,

Figure 3 is a side elevation of the keyboard shown in Figure 1, and

Figure 4 is a top plan view of a typical key for this keyboard.

This invention is a keyboard for musica1 instruments such as the piano, pipe organ, and electric organ. Its 24 digitals per octave are designed for fingering the harmonics of either the American Quartertone Temperament defined herein, or the more familiar Equal Quartertone Temperament.

The 24 digitals of the decatonic keyboard are divided into three types-10 decatonic digitals, 7 upper prismatic digitals, and 7 lower prismatic digitals. The term prismatic signifies tonol coloring foreign to the decatonic scale. It is analogous to the familiar term chromatic,

which is used to signify tonal coloring foreign to the diatonic scale.

For convenience in describing digital placements, the decatonic keyboard is theoretically divided into horizontal thirds-top, bottom, and middle. As indicated in Figures 1 and 3, the top third is farthest from the player, or in the rear, the bottom third is nearest the player, or in front, and the middle third lies between the top and bottom third.

As seen in plan, Figure 1, all of the decatonic digitals I0 extend through the top, middle, and

bottom thirds of the keyboard. The letter names for these digitals, which intone the decatonic scale, areC, Ct, D plus, Di plus, F, Ft, G, Gt plus, A plus, and B.

' The upper prismatic digitals II which intone a pseudo-diatonic scale, are seen to occupy positions in the top third only. The letter names for these digitals areC plus, D, E, F plus, G plus, A, and At plus.

The lower prismatic digitals I2, which also intone a pseudo-diatomic scale, are seen to occupy positions in the bottom third only. The letter names for these digitals areC# plus, Di, E plus, Ft plus, Git, At, and B plus.

The decatonic digitals l0 are about twice as wide and three times as long as the prismatic digitals H and I2.

When a single prismatic digital I I or l2, either upper or lower, occurs between two decatonic digitals, it is centered between these two decatonic digitals, and superimposed half through one and half through the other in exactly the same way that a black digital on the piano is centered between two white digitals and superimposed half through one and half through the other. Thus, in Figure 1, the upper prismatic digital A is centered between Gt plus and A plus. The lower prismatic digital B plus is centered between B and C.

When both an upper and a lower prismatic digital occur between two decatonic digitals III, the higher-pitched prismatic digital is superimposed through the higher-pitched decatonic digital, and the left hand edges of both digitals are aligned, as Gt is superimposed through Gt plus,

or as D is superimposed through D plus. Also the deeper pitched prismatic digital is superimposed through the deeper-pitched decatonic digital, and the right hand edges of both are aligned, as Ct plus is superimposed through Cit, or as G plus is superimposed through G.

The plane of the keyboard is a horizontal level serving as a hypothetical foundation for digital manipulation. In front elevation, this plane appears in lineal profile as the left-to-right center line of Figure 2, where it is seen defining the bottom level of the upper prismatic digitals II, and the top level of the lower prismatic digitals l2. The same fact is evident in the side elevation, Figure 3., where the top third only of the decatonic digitals I is also seen to lie in the plane.

The level surface of the white digitals might be regarded as the central plane of the present day piano.

The side elevation of the decatonic keyboard, Figure 3, shows the three types of digitals in profile. The top level of the upper prismatic digitals H is seen to be higher than the rest of the keyboard. These digitals H (similar to the black digitals of the piano) superimposed through the central plane of the keyboard. The top level of the lower prismatic digitals l2 coincides with the central plane.

The ends nearest the player of both the upper and lower prismatic digitals slant downward and forward toward the player in the same manner as the ends of the black digitals on the standard piano. However, in the case of the lower prismatic digitals I2 only, the ends farthest from the player slant downward and sloping surface of these nether ends thus presented for manipulation is less in area than the forward ends of the same digitals.

The most distinctive feature of the keyboard is the partial curvature of the decatonic digitals ID, as shown in side elevation in Figure 3. The contour along the top third of these digitals coincides with the central plane. The contour then falls forward, toward the player, and downward, below the central plane, at a gently slanting curvature through the middle third of the keyboard. Continuing forward, the contour of the decatonic digitals slopes down at a more acute straight slant through the bottom third of the keyboard.

Two main logical approaches, complementary in nature, are implicit in the 24tone octave. One of these is integral, the other dual. On the decatonic keyboard, the integral logic is expressed in the digital arrangement, while the colors of the digitals display the dual logic.

In the integral logic, the 24 tones of the octave are regarded as derived from a single closed cycle of 24 medial s xths. The principal scale of the integ l m1.- .,.;.ir tliio decatcnic scale, lntoncd by the 10 decatonic digitals l0, supplemented by 14. coloring tones, intoned by the prismatic digitals ii and i2.

On the other hand, the Eli-tone octave is regarded in the dual logic as derived from two separate closed cycles of 12 fifths. The tones of each of these cycles are interposed between the tones of the other, in alternate order. The principal scale for each of these 12mm chromatic octaves is a 'l-tone diatonic scale supplemented by chromatic tones.

The color logic of the decatonic keyboard is simplified by the fact that the 12 white and black digitals intone the same pitches as the white and black digitals of the present day piano. The

rearward. The

ondary) white digitals intone a diatonic scale, and the black digitals a pentatonic scale. This white and black set of digitals constitutes the primary keyboard, on which the white digitals are primary diatonic digitals, and the black are primary chromatic digitals.

In contradistinction to the primary keyboard of 12 tones is a similar secondary keyboard of 12 tones. As shown in Figure l, the digitals of this secondary keyboard are interposed between the digitals of the primary keyboard. The digltals of the secondary keyboard are distinguished by colors other than white and black, such as bud and brown. The buff digitals, which intone a diatonic scale, are called secondary diatonic digitals. And the brown digitals, which intone a pentatonic scale are called secondary chromatic digitals.

The traditional Ionian Mode (key of C) is intoned by the primary diatonic digitals, starting with CC, D, E, F, G, A, B, and C.

The same Ionian lvlode is iii-toned by the secondary diatonic digitals (paralleling the foregoing scale a medial third or semi-iifth more acute in pitch), starting with D# plus-Da t plus, F plus, G plus, Git plus, A# plus, C plus, D plus, and D# plus.

While the decatonic digitals include all four colors, as shown in Figure l, the upper prismatic digitals include only diatonic (primary and sec ondary) digitals, and the lower prismatic digitais include only chromatic (primary and secdigitals. In other words, only white and buff digitals occur in the top third of the keyboard, and only black and brown in the bottom third.

Four contraction points exist in the American Quartertone Temperament. A dot I3 is inlaid at the center of each of the four deoatonic digitals defining these points of contraction. Black dots markthe white digital C and the buff digitals D plus and G-t plus; a white dot marks the black digital F#. This is illustrated in Fig. 2.

In the table of vibration rates which follows, dotted digitals are specified by asterisks in the right hand margin.

Equal Quartertone Temperament, in contradistinction to American, may be defined as the simple division of the octave (ratio 1:2) into 24 equal intervals, or just double the number of equal intevals occurring in an octave of the present day piano. These intervals may be mathematically defined as powers (from 0 to 24) of the 24th root of 2.

While the American Quartertone Temperament is more complex than the Equal, it is also less tempered. As shown in the following table, its 24 tones are mathematically spaced by selected powers of the 133th root of 2ratlo 1: 1.00535 or 187: 188. This ratio is the Interval Unit of the American system.

The musical intervals, or quartertones, between adjacent digitals are of two kinds-(l) the semihemitone of 5 interval units and (2) the demisemitone of 6 interval units.

Without propounding the theory of this new temperament, following is a table of vibration rates for the octave pictured in Figure 1.

It will be observed that International Pitch is adhered to, with the value for A very faintly sharpened (435.64 vibrations per second).

By a transposition, not explained here, the fundamental generator of the system is pitched at V. P. S., as indicated in the value, two octaves higher, assigned to G plus-400 V. P. S.

Table of vibration rates for the American Quartertone Temperament Interval Prunary Secondary white and Vibrations bull and 2 x29? black per second brown 13051 dlgltals digitals root of 2) 266. 74 0 plus 5 Db minus Cit 275. ll Db 282. 84 0e plus 16 D minus D 292. 04 22 299. 93 D plus 27 Eb minus D# 308. 04 32 Eb 318.05 Di? plus 38 E minus E 6.63 43 337. 26 E plus 49 F minus F 346. 42 54 355. 73 F plus (lb minus Flt 367. 29 Gb 377. 23 1% plus G minus G 389. 47 76 400 G plus 81 Ab minus Gk 413.02 87 Ab 424.16 Git plus 92 A minus A 435. 64 97 449. A plus 103 Bb minus At 461. 92 108 Bb 476. 96 Alt plus 114 B minus B 489.84 119 503.08 B plus G minus 0 519. 44

Figures 3 and 4; represent a typical construction of the decatonic digitals Hi. The digital II] is formed with an elongated body I4, with a rectangular cutout l5 extending along one-third of one edge at one end of the body M, a full width section 16 extending along the center one-third of the body l4 and a second rectangular cutout I1 extending along one-third of the opposite side at the opposite end of the body [4.

The exact configuration illustrated is regarded as the optimum, but some of the desirable results inherent in this disclosure may be obtained by various slight modifications including some departure from the exact configuration shown, and it is therefore requested that the scope of the invention should be regarded as limited only by the and a. second rectangular cut-out along the opposite side at the other end of said digital, said digitals so arranged that the cut-out of one digital cooperates with the cut-out of the adjacent digital to form Wider openings between said digitals, a row or" short digitals extending upwardly from said wider openings along one end of said first digitals and another row of short digitals extending up wardly from said wider openings along the other end of said first digital-s.

2. A keyboard formed of a plurality of elongated digitals, each of said digitals formed with a rectangular cut-out along one side at one end there of, and a second rectangular cut-out along the opposite side at the other end of said digital, a row of short digitals extending upwardly from said openings at one end of said first digitals and a second row of short digitals extending upwardly from said openings at the other end of said first digitals, said first digitals tapering downwardly toward the forward end thereof whereby the upper edge of the digitals of the forward row will lie in a plane above the forward edge of said first digitals and below the plane of the upper edge of the rear row of short digitals.

3. A keyboard formed of a plurality of elongated digitals, a row of short digitals extending upwardly from between said first dlgitals at one end thereof and a second row of short digitals extending upwardly from between said first mentioned digitals at the other end thereof, said first mentioned digitals tapering downwardly and forwardly from the forward end of said first row of short digitals and below the forward end of said second row of short dlgitals.

4. A keyboard formed of a plurality of elongated digitals, each of said digitals formed with a rectangular cut-out on one side at one end thereof, and a second rectangular cut-out along the opposite side at the opposite end of said digital, a row of short digitals extending upwardly in said cut-outs along one end of said first digitals and a second row of short digitals extending upwardly from said opening at the other end of said first digitals.

LYMAN YOUNG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,284,868 Heaney June 2, 1942 FOREIGN PATENTS Number Country Date 2078 France March 15, 1817

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