Ground

A passacaglia is a promise: the bass — here four descending notes, A G F E, the old lament figure — repeats unchanged while everything above it is free. Twelve cycles: the ground alone, then harmony, then a voice that enters shyly, learns to run, climbs to a doubled-octave climax at cycle VII, and thins back to almost nothing before the final chord turns, unannounced, to A major.

The score is data and the promise is tested: a machine proof confirms the ground recurs bit-identically in all twelve cycles, and that every note above it is legal for its bar's harmony. The freedom is real because the constraint is. Your browser synthesizes the piece live from that same verified score.