EDO

An abbreviation for Equal Division of the Octave, it is a unit used to describe how an octave can be divided into equal parts, often for the purpose of defining a microtonal scale or tonality system. Traditional Western European music uses 12-EDO, that is, each octave is divided into 12 equal half-steps (semitones). Music that uses equal quarter tones uses 24-EDO. See also pitch delta.