The opening sound is low, dark, and almost bare. After the half-second of silence, the organ enters as weight before it enters as ornament. By 0:08 the ear has enough of the ground to feel the room change around it: sustained tone, slow air, and a bass line that seems to make the floor audible.

Through the first minutes, the sound grows by layering force rather than by percussion. The pulse is very regular, but the body hold is weaker than the pattern hold; that matches the performance. The organ gives the listener a tread, not a groove. It is countable, severe, and suspended inside resonance.

The surface begins to thicken around 2:30 without becoming noisy. Higher lines sharpen the upper edge while the center stays warm and dark. The sound is almost entirely harmonic, with little percussive bite, so the ear reads motion through changes in density, register, and harmonic pull instead of drum-like attack.

Sustained tone has become the main pressure system by 4:40. Notes lean against each other until harmony has to move, and each return of the ground resets the room without emptying it. The texture is spacious in the literal sense, but it is not light; the organ's bass weight keeps giving the air a downward pull.

The fugue entry around 7:30 changes the sonic problem. The sound no longer depends on one low ground carrying everything from below. Lines begin to answer and chase, and the organ's mass turns counterpoint into a physical structure. Lower registers widen the instrument; upper entries harden the top of the space with light.

Past 9:00 the density stays clear enough that the listener can hear architecture forming inside resonance. The force is mostly sustaining, not explosively building, which makes small releases feel larger than they would in a faster or more percussive recording. The sound keeps its authority by refusing blur.

In the last stretch, from about 11:20, the organ spends its stored weight. The pattern breaks near the final cadence, and the terminal silence after about 12:35 completes the sound argument. The room is no longer being filled, but the bass shape still seems to remain in it.