PC Set Analysis

The set-theory reading of a chord: normal form, prime form, the 12-bit chroma, and the matching Forte set class from the full 352-row table with its symmetry properties parsed out. Keyed on a computed prime form rather than the interval vector, so a major triad is identified as a major triad — an interval-vector lookup cannot separate a set from its inversion, which is why the usual implementation reports one as the other.