pitch-class set

Group of notes considered entirely from the point of view of their pitch classes; that is, independently of their tonal function, the octave in which they occur, the order in which they occur, or the number of occurrences of each pitch in the set. By convention, pitch classes are numbered from 0 to 11, with 0=C natural/B sharp, 1=C sharp/D flat and so on. Pitch-class sets are labelled with two digits, the first indicating the number of pitches in the set, and the second the number of the set in the list of all possible sets. For example, the pitches C, E, and G (0, 4, and 7) form the set 3-11. If transpositions and inversions of sets are considered to be equivalent to one another, the 12 chromatic notes can form a total of only 234 distinct pitch-class sets. Pitch-class set analysis describes music entirely on terms of the pitch-class sets identifiable in a piece and the relationships between these sets, and is principally used in the analysis of atonal music. See Allen Forte; set complex; subset/superset; similarity relation.