Enharmonic scale

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Enharmonic scale [segment] on C.[1][2] About this sound Play [2] Note that in this depiction C and D are distinct rather than equivalent as in modern notation.
Enharmonic scale on C.[3]

In music theory, is, at its simplest, "a chromatic scale with each tone written in manifold notation".[4] Relatedly, the enharmonic scale is, "an [imaginary] gradual progression by quarter tones," or any, "[musical] scale proceeding by quarter tones".[3] More properly dieses or 'divisions',[2] nonexistent on modern keyboards and originating in the diminished seventh chord.[1] More broadly, an enharmonic scale is a scale in which (using traditional notation) there is no exact equivalence between a sharpened note and the flattened note it is enharmonically related to, such as in the quarter tone scale. As an example, F sharp and G flat are generally equivalent in a chromatic scale, but they would be distinguished in an enharmonic scale. See: musical tuning.

Diesis defined in quarter-comma meantone as a diminished second (m2 − A1 ≈ 117.1 − 76.0 ≈ 41.1 cents), or an interval between two enharmonically equivalent notes (from C to D). About this sound Play

Consider a scale constructed through Pythagorean tuning. A Pythagorean scale can be constructed "upwards" by wrapping a chain of perfect fifths around an octave, but it can also be constructed "downwards" by wrapping a chain of perfect fourths around the same octave. By juxtaposing these two slightly different scales, it is possible to create an enharmonic scale.

The following Pythagorean scale is enharmonic:

Note Ratio Decimal Cents Difference (Cents)
C 1:1 1.00000 0.00000
D♭ 256:243 1.05350 90.2250 23.4600
C♯ 2187:2048 1.06787 113.685
D 9:8 1.12500 203.910
E♭ 32:27 1.18519 294.135 23.4600
D♯ 19683:16384 1.20135 317.595
E 81:64 1.26563 407.820
F 4:3 1.33333 498.045
G♭ 1024:729 1.40466 588.270 23.4600
F♯ 729:512 1.42383 611.730
G 3:2 1.50000 701.955
A♭ 128:81 1.58025 792.180 23.4600
G♯ 6561:4096 1.60181 815.640
A 27:16 1.68750 905.865
B♭ 16:9 1.77778 996.090 23.4600
A♯ 59049:32768 1.80203 1019.55
B 243:128 1.89844 1109.78
C' 2:1 2.00000 1200.00

In the above scale the following pairs of notes are said to be enharmonic:

  • C♯ and D♭
  • D♯ and E♭
  • F♯ and G♭
  • G♯ and A♭
  • A♯ and B♭

In this example, natural notes are sharpened by multiplying its frequency ratio by 256:243 (called a limma), and a natural note is flattened by multiplying its ratio by 243:256. A pair of enharmonic notes are separated by a Pythagorean comma, which is equal to 531441:524288 (about 23.46 cents).

The enharmonic genus is only loosely related to enharmonic scales, being a scale that has a pitch distinction too fine to accommodate with flat and sharp notation.

Musical keyboards which distinguish between enharmonic notes are called enharmonic keyboards.

[edit] Sources

  1. ^ a b Moore, John Weeks (1854). Complete Encyclopædia of Music, p.281. J. P. Jewett. Moore cites Greek use of quarter tones until the time of Alexander the Great.
  2. ^ a b c John Wall Callcott (1833). A Musical Grammar in Four Parts, p.109-10. James Loring. "In some examples of the Enharmonic Scale, the Intervals, F flat and E sharp, as also C flat and B sharp, are inserted; but they do not belong to that scale. This distance...is smaller than the Quarter-tone."
  3. ^ a b Louis Charles Elson (1905). Elson's Music Dictionary, p.100. O. Ditson Company.
  4. ^ John Henry Cornell (1907). The Practice of Sight-Singing, p.6. G. Schirmer.

[edit] External links

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