Organ prelude in A minor

The task

Compose a organ prelude in A minor, 85 BPM andante, 4/4, about 88 bars and about three and a half minutes, scored for organ in 3 voices. Texture: harmonic motion over a sustained pedal note. Open with 4 bars of organ alone, then layer the other parts in one at a time. The main section runs on a 4-bar diatonic loop of…