Johann Sebastian Bach (1685-1750): Das Wohltemperierte Clavier, book 2. 21 of the 24 preludes and fugues of the second book of the �Well-Tempered Clavier�, BWV 870-872, 875-880, 882-893. All the music is in the hand of the composer, with the exception of the preludes and fugues in C minor, D minor, E major and G major, and part of the F major prelude (f. 8r), which are in the hand of his second wife, Anna Magdalena Bach. The music is written on two staves of 5 lines each, the upper part of which in the C clef, except ff. 1 and 13-14v where the G clef is employed.