SetClass

Explore the building blocks of modern harmony. This app lets you see, hear and manipulate pitch class sets, the foundation of post-tonal and atonal music theory. EXPLORE • Tap notes on the pitch wheel to build any chord or scale. • See the Forte number, prime form, normal form and interval vector. • Check transpositional and inversional symmetry. • Open the K/Kh complex of any set to see which set classes include it or its complement. FIND • Tap notes on a keyboard, or type a Forte number (3-11, 6-Z44) or pitch-class numbers (0 4 7). • Browse all 224 Forte set classes, with Z-relations, filtered by size. TRANSFORM • Transpose, invert and multiply (M5, M7) any set. • Morph smoothly from one set to another. CREATE • Generate sets by cardinality, symmetry and density. • Arrange sets into rhythmic sequences using P, T, I, R and RI operations, with every inversion level. • Build a serial matrix from rows of 2 to 12 notes. • See each set as geometry in tonal space, with symmetry axes. • Export to MIDI and MusicXML. LEARN • A built-in theory guide. • Analysis examples from Debussy, Schoenberg, Stravinsky, Berg, Messiaen and more, with links to scores. Built for students, composers and theorists, from first-time learners to advanced analysis.