This is my own transcription of this famous harpsichord piece from François Couperin (1668-1733). The piece "Passacaille en si mineur" (Livre II, 8ème ordre) was composed in 1717.
On the pedalboard of the real organ, you can use the low A and B below the usual first C. Here, it is not possible, so I had to transpose the whole piece from B min. to C min.