One line begins alone, low on the organ, walking its theme down a step at a time.

The theme comes round again, and this time a second voice moves above it — same ground every time, more growing on top.

The registration leans brighter: quick figures up top, the floor underneath still dark and steady.

Now the theme sits in the pedals, and the bottom of the sound gets heavier — long notes leaning into the room.

Fast running notes spill over a calm harmonic bed: motion on top, stillness underneath.

It settles — fewer notes, more air between them, the theme still pacing along below.

A first real crest: the lines swell together, deeper stops underneath, and the room fills.

It pulls back into lighter, brighter stops, the pressure easing after the peak.

It gathers again and this time it holds nothing back — full organ, deep bass under wide chords, the biggest sound so far.

Then it thins: the same instrument, aired out, each voice easier to follow one by one.

The rhythm tightens and leans, small pushes off the steady beat while the bass keeps the floor.

The texture thickens again — voices piling up, chords starting to hold — a bigger build than the last.

The pressure lets go into brightness: quick, agile lines and lighter footing.

The full sound is back, chordal this time, the bass carrying real weight beneath it.

Out of that close the fugue begins almost without a breath — one voice alone, carrying a shape from the opening theme.

The next voices enter one after another, each taking the same figure; the stack rebuilds floor to ceiling.

Through the middle of the fugue the figure keeps trading registers; the surface stays full and the floor never wavers.

The closing stretch: wide chords over a striding bass, the whole instrument opened up.

The last chord lets go, and the room carries it out, thinning slowly to nothing.