pitch class set

A pitch class set is a collection of musical notes, focusing on their unique pitches without regard to octave differences. For example, all C notes across various octaves belong to the same pitch class, labeled 'C.' In music analysis, pitch class sets group notes based on their pitch classes to explore relationships and patterns within compositions. This concept helps musicians and theorists understand the structure of atonal or modern music, where traditional tonal centers aren't present. Essentially, it’s a way to organize and analyze pitches based on their sound identity, regardless of their octave placement.