Delta scale
The δ (delta) scale is a non-octave repeating musical scale. It may be regarded as the beta scale's reciprocal since it is, "as far 'down' the (0 3 6 9) circle from α as β is 'up.'"[1] As such it would split the minor second (presumably 16:15) into eight equal parts of approximately 14 cents each Play (help·info). This would total approximately 85.7 steps per octave.
The scale step may also precisely be derived from using 50:28 (25:14, 1003.8 cents, A♯, Play (help·info)) to approximate the interval 3:2⁄5:4, which equals 6:5 (E♭, 315.64 cents, Play (help·info)). Thus the step is approximately 13.946 cents and there are 86.049 per octave.
(Play (help·info))
The Bohlen–Pierce delta scale is based on the tritave and the 7:5:3 "wide" triad (Play (help·info)) and the 9:7:5 "narrow" triad (Play (help·info)) (rather than the conventional 4:5:6 triad). Notes include:[2]
- 1:1 Play (help·info)
- 25:21 Play (help·info)
- 9:7 Play (help·info)
- 75:49 Play (help·info)
- 5:3 Play (help·info)
- 9:5 Play (help·info)
- 15:7 Play (help·info)
- 7:3 Play (help·info)
- 25:9 Play (help·info)
- 3:1 Play (help·info)
interval name | size (steps) |
size (cents) |
just ratio | just (cents) |
error |
minor third | 23 | 321.23 | 6:5 | 315.64 | +5.59 |
major third | 28 | 391.06 | 5:4 | 386.31 | +4.75 |
perfect fifth | 50 | 698.32 | 3:2 | 701.96 | -3.63 |
See also[]
Further reading[]
- Bohlen, Heinz: "13 Tonstufen in der Duodezime", Acustica, vol. 39 no. 2, S. Hirzel Verlag, Stuttgart, 1978, pp. 76 – 86. (in German)
Sources[]
- ^ Taruskin, Richard (1996). Stravinsky and the Russian Traditions: A Biography of the Works through Mavra, p.1394. ISBN 978-0-520-07099-8.
- ^ "What about BP tonality?", The Bohlen-Pierce Site.
- Equal temperaments
- Non–octave-repeating scales
- Music theory stubs