Equiheptatonic

Equiheptatonic scales are heptatonic scales with 7 roughly equally spaced tones per octave.

They are usually not exactly equally spaced, but deviate from equal by small amounts, often to improve the tuning of 3/1 and 5/1.

Musical traditions that make use of equiheptatonic scales include:

• Eastern Angolan music
• Ancient Chinese music
• Ancient Greek auloi music
• Chopi music from Mozambique (inspired Erv Wilson to create the mavila temperament)
• Mande music from West Africa
• Shona music from Zimbabwe
• Lower Zambezi music
  • Nyungwe music
• Cambodian classical music (disputed)
• Laotian classical music (disputed)
• Thai classical music (disputed)
• Vietnamese classical music (disputed)

Note that just because a tradition has an equiheptatonic scale doesn’t mean it uses it exclusively. They often have other tunings 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 equiheptatonic scale equals 7edo, which is popular with modern Western xenharmonic composers.

See also

• Equipentatonic
• African music
• Macrotonal NEJI edos: the 7-tone ones are examples of equiheptatonic scales