Set (music)

[2] A set by itself does not necessarily possess any additional structure, such as an ordering or permutation.

Sets of higher cardinalities are called tetrachords (or tetrads), pentachords (or pentads), hexachords (or hexads), heptachords (heptads or, sometimes, mixing Latin and Greek roots, "septachords"),[5] octachords (octads), nonachords (nonads), decachords (decads), undecachords, and, finally, the dodecachord.

[6] In the theory of serial music, however, some authors[weasel words] (notably Milton Babbitt[7][page needed][need quotation to verify]) use the term "set" where others would use "row" or "series", namely to denote an ordered collection (such as a twelve-tone row) used to structure a work.

[citation needed] The fundamental concept of a non-serial set is that it is an unordered collection of pitch classes.

[13] However, in 2017, music theorist Ian Ring discovered that there is a sixth set class where Forte and Rahn's algorithms arrive at different prime forms.