Dave4Guild said, in part:

But I had grade 8 on Piano when I was twelve, and personally I would back Bach. I think he had the greater intellect of any of these rather averagely talented professions.

This has nothing whatever to do with which musician had the greater intellect. Nor has it anything to do with which is the better piece of music.

Bach's piece is long, long in the public domain. Certain editions published within the appropriate recent time frame may be copyrighted, but it's the physical representation, and any editorial liberties taken with Bach's music (publishers do it all the time) that's copyrightable.

Mathew Fisher's piece, regardless of its musical value or lack thereof, is an original piece even if inspired by Bach, or even if some bass figure is literally quoted from Bach.

Dave Oesterreich