Equal Division of the Octave (EDO)

EDO stands for Equal Division of the Octave: the number of equal pieces, or intervals, into which an octave is divided.

Traditional Western harmony is based on equal temperament, another method used to describe tonality systems, or 12-EDO, as the traditional scale from C-C is made up of twelve steps spread across the seven notes in the scale.

For example, between the notes A and B there are two steps, but between B and C there is one step. This is because in 12-EDO, each step represents a half-step (semitone), and there are two half-steps between A and B according to standard equal temperament, but only one half-step between B and C.

Other tonality systems can have different equal divisions of the octave, for example, in 24-EDO each octave division is a quarter tone. However, the only tonality system in Dorico Elements is 12-EDO.