0:00-0:08 Ground stated

The piece opens by isolating the rule. A brief silence gives way to the low passacaglia line, and the first return makes the listener understand that the structure will be built from recurrence rather than contrast.

0:08-2:30 Variations under one floor

The early form keeps the bass ground audible while the upper voices change density and direction above it. Each variation works as a different pressure on the same floor: not a new scene, but a new way of carrying the original tread.

2:30-4:40 Accumulation without rupture

The middle passacaglia thickens the structure while preserving the law. Harmonic turns, brighter upper entries, and darker descents make the form feel increasingly crowded, but the repeated ground prevents the music from scattering.

4:40-7:30 Mechanism tightened

The later passacaglia makes recurrence feel like a condition. The listener is no longer waiting for the ground to return; the ear is measuring what each return has made heavier. This stretch prepares the fugue by pushing the ground from pattern into internal discipline.

7:30-11:20 Fugue internalizes the law

Around 7:30 the structural job changes. The repeated bass no longer simply carries variations from below; the fugue turns its force into entries, answers, pursuit, and fitted counterpoint. The old tread becomes a rule shared by every line.

11:20-12:35 Closing authority

The final section compresses the history of the piece into closure. The organ gathers the passacaglia's weight and the fugue's multiplying lines into one last command, then releases into the terminal silence after about 12:35.