Equipentatonic
Equipentatonic scales are pentatonic scales with 5 roughly equally spaced tones per octave.
They are usually not exactly equally spaced, but deviate from equal by small amounts, usually to improve the tuning of 3/1.
Musical traditions that often make use of equipentatonic scales include:
- Aka music from Central Africa
- Dagarti, Lobi and Senufo music from West Africa
- Indonesian gamelan music (slendro scales)
- Southern Ugandan music
Note that just because a tradition has an equipentatonic scale doesn’t mean it uses it exclusively. Indonesian gamelan for example uses equipentatonic slendro scales, but also far-from-equal pelog scales too. Also, the term “scale” here is used loosely, because many, perhaps the majority, of musical traditions don’t use scales, but use something else like tetrachords, raag, etc. that scales can only loosely model.
An exactly equal equipentatonic scale equals 5edo, which is popular with modern Western xenharmonic composers. Sevish recommends 5edo as a tuning for those newly exploring beyond 12edo.
Many equipentatonic scales can be considered omniconsonant scales.
Equipentatonic scales in edos
All multiple-of-5 edos (5, 10, 15, 20, 25…) contain the exactly equal 5edo equipentatonic scale.
In most traditions that use them, equipentatonic scales are slightly unequal and slightly closer to just (rarely slightly further from, but only by a tiny amount). There are a diverse array of those used in different regions.
For that reason, it might be more fruitful for composers to explore edos with equipentatonic scales that share those characteristics: that is, after all, its own diverse array of subtly different equipentatonic scales.
Such edos include:
- 1edo to 40edo
- 40edo to 60edo
42, 44, 47, 49, 52, 54, 57, 59
- 60edo to 80edo
62, 64, 67, 69, 72, 74, 77, 79
- 80edo to 100edo
82, 83, 84, 87, 88, 89, 92, 93, 94, 97, 98, 99
From the list it can be seen that edos with this type of equipentatonic scale are often runoff edos [idiosyncratic term ], they are often dual-fifth edos and they often support superpyth or a related temperament. None of these things are always true: just true more often than chance.
See also
- Equiheptatonic
- African music
- Macrotonal NEJI edos: the 5-tone ones are examples of equipentatonic scales