US10217A - Kevolving musical scale - Google Patents

Description

i. UNITED STATES PATENT OFFICE.

SAML. D. TILLMAN, OF SENECA FALLS, NE\V YORK.

REVOLV'ING MUSICAL SCALE.

Specification of Letters Patent No. 10,217, dated November 8, 1853.

To LZZ whom z'zf may concern:

Be it known that I, SAMUEL D. TILLMAN, of Seneca Falls, Seneca county, and State of New York, have made a new and useful Instrument for Measuring and Illustrating Musical Intervals, and that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing, illustrating the same.

The nature of my invention consists in an improved method of measuring and illustrating musical intervals, and all relations between the fixed chromatic scale and the diatonic scale of any given key. This I effect by the combination of two or more circular disks or rings of metal, wood or pasteboard having arms leading to a common center.

Figure l represents a front view of the instrument; the outer row of letters seen are on the lower disk, (intended to be staticnary,) and around the center of which revolve a graduated ring, and 'also another disk, either one of which may be used in connection with the lower disk; both are fixed to the lower disk by means of the same female screw. In illustrating the musical intervals used in the piano, and all other instruments having l2 keys within the octave, the upper and lower disks only need be used.

In practice the piano is tuned more perfect on some keys than on others, as it is impossible to have all correct with only twelve keys in the octave; but as each of these twelve keys are in fact often used as the tonic or key-note, it follows that they must in theory all bear the same relation to each other; each in turn must represent a tone, a semitone, stand for the sharp of the note below, and the flat of the note above it; and therefore in represent-ing these mu* sical intervals by distances or degrees on a circle, I divide the circle on the outer disk into twelve equal parts, numbered like acomnion clock face, each of which represents the interval of a semitone, and two of them united would mark a tone. In the diatonic scale which contains the natural notes of the octave, the intervals commencing at C as the tonic or key-note, are by the letters C, D, E, F, G, A, B, on the lower disk. Here we find five tones, or intervals of the same length, and also two semitones. The upper disk has upon it the seven notes or intervals which are alike in every octave represented by arms or projections, to which are added the syllables used in singing them-do, re, mi, fa, sol, la, si. The do, which naturally follows in singing, belongs to the next series or octave. Do is always the tonic or key-note and when that syllable is placed opposite C on the outer disk, all the other syllables will be opposite a letter on that disk; but when do7 is opposite any other letter, some of the other syllables will not fall on letters, owing to the unequal division of the scale, but will be found opposite some letter sharped or flatted; thus the upper and lower disk will show what sharps or flats are produced in every key; for instance, if do 1 is opposite D, a syllable will be opposite F#- and Cit; therefore in the key of D, there are two Sharps. So when do is opposite F, one syllable falls on Bb; therefore in the key of F there is one flat.

I now proceed to show the uses of the ring in connect-ion with the lower disk. No keyed instrument, like the piano, can be in perfect tune, because the intervals are not of the same length, as represented by the divisions used above. If we divide the lower disk and the ring each into sixty degrees or equal parts, we shall get not the true notes, but a very near approximation; and thatnumber of parts being on a common clock face, it will not be difficult to use these divisions, which I shall call commas, although they are a little less than a true comma, as it would berepresented by distance on a circle. In the first scale used, I assumed that the interval between each tone was of the same length, and it was twice that of the semitone; but the first two intervals vary by a comma: from C to D is l0 commas; but from D to E is only 9; therefore the truer E would be fixed at one comma lower than in the first scale described; but the diatonic interval, called a semitone, is to be represented by six commas, which brings the F in both divisions on the same point. In this scale also the truer A and B are found one comma below that in the first named scale. The do and other syllable sung are inscribed on the ring in their true places, according to this division, and on turning the ring so as to have the syllable do fall on any letter or division, except C, it will be seen at what points on the fixed scale the remaining syllables should fall. The ring be required.

bears the same relation to the division into sixty parts on the lower disk, which the upper disk bears to the division into twelve parts also on the lower disk. The arms within the ring, which support it in its axis, show the divisions made in the scale by the common chords, and point out the chord of the third and the fifth in any key whatever on the fixed scale: so other chords may be represented on the moving ring or moving disk.

A truer division of the scale or circle would be into 53 equal parts when the interval of a major tone would be represented by 9; a minor tone by 8, and a diatonic semitone by 5 commas, which division of the scale I claim to use when making the instrument for the use of the more scientific musician.

The divisions on the upper disk and ring may be all represented on one disk, which may be without the projection on that I now use, by substituting marks which would be equally distinct, and illustrative: all the flats and Sharps in their true places on the scale of minutest division may also be represented. Lines drawn from the center of the moving disk, like radii may be so arranged as to represent the chords of the third and fifth also any others which may The tonometer illustrates equally well the intervals in any minor key for when do is the tonic in the major key, la is the tonic in the relative minor key, in which last ke the ear sometimes requires the syllables fa and sol to be raised a semitone higher than represented; for instance in the key of A-minor, la falls on A and fa on F# and sol on G# in ascendin the scale, but in descending fa and sol fall on F and G respectively.

My simple rule for finding the notes of the diatonic scale in any major key is: When the tonic is on an even number, the next two notes are on even and the rest on odd numbers. Vhen the tonic is on an odd number vice versa. Thus in the key of C, 1Q, 2, 4, 5, 7, 9, 11. In the key of G, 7, 9, 11, 12, 2, 4,6.

Vhat I claim as my invent-ion, and for which I ask to secure Letters Patent, is'- The employment of a fixed disk, in which the musical intervals within the octave are represented by divisions of a circle, and the letters commonly used to designate the notes of the fixed scale, in combination with one o1' more arms, disks or rings, rotating around the center of the circle of the fixed disk; on which rotating arms,disks or rings, are the true and tempered divisions of the diatonic scale, so arranged that the relations of these divisions of the diatonic scale, with those on the fixed scale may be clearly seen when the point designating the tonic or key note on the moving scale is placed opposite any of the divisions of the fixed scale, substantially in the manner and for the purposes as hereinabove set forth.

SAMUEL D. TILLMAN.

Witnesses:

I. H. UNDERHILL, E. T. TYLER.

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