“I am presently collecting the fugues of Bach – not only of sebastian, but also of Emanuel and friedeman”, wrote Mozart to his father in April 1782. This could be a hint that the Six Three-Part Preludes and Fugues were derived from this collection: Mozart wrote string-trio arrangements of two preludes and five fugues by Johann Sebastian Bach, and of one fugue by Wilhelm Friedemann Bach. This apparently plunged him into such a creative mood that he simply wrote the missing preludes himself. It is...