The Bach Busters series 'unlocks' some of the less well known but equally beautiful Preludes and Fugues from J. S. Bach's Well Tempered Clavier, through transposition and subtle re-notation.
Fugue III originally in C# maj now in C maj
Fugue IV originally in C# min now in D min
Fugue XIII originally in F# maj now in F maj
Fugue XV III originally in G# min now in G min