Incomposite interval

[2] In another place, Aristoxenus clarifies that the mere discrimination of magnitudes by the senses is no part of a complete understanding of the subject.

In such a case the function of the note λιχανός is such that "the 'nature of μελῳδία' somehow requires that it should leap forward at least as far as μέση, without touching down anywhere in between.

[4] The nature of the chromatic genus, too, is an attribute of the kinēsis phonēs (Ancient Greek: κίνησις φωνῆς, "potentiality of the sounds"), so that certain melody types are "brought into being".

"None of these consists in the voice's coming to rest at points separated by distances of specific and determinate sizes".

It is in the nature of the enharmonic to have the following division: a diesis—that is, half of a semitone—and then another diesis, together equal to a semitone, and then the remainder of the tetrachord, a whole, incomposite ditone.

Following the strict definition found in Nicola Vicentino's L'antica musica ridotta alla moderna prattica (1555), all intervals larger than the major third (or ditone) are necessarily composite.

However, for the purpose of his discussion of the "modern practice" of the 16th century, he extended the definition to include larger intervals within the octave.