W.A. Mozart - Sketches and Addendum for Great Mass in C minor, K. 427

1) [MIDI] A short fugal exposition (KV 417B, 1) and several sketches of contrapunctal studies based on the theme of the "Cum sancto spiritu" fugue - written from 1782 to 1785.
2) [MIDI] 1783 sketch (Skb 1783γ - Sk 1783a) for an 8-voice double fugue apparently for strings and chorus which Robert Levin used as the basis of the "Crucifuxus" in his completion of the mass.
3) [MIDI] 1784 sketch (KV 417B, 6) for an 5-voice fugue for chorus and continuo which Robert Levin used as the basis of the "Et unam sanctam" in his completion of the mass.
4) [MIDI] 1783 sketch (KV 417B, 5) for an 8-voice fugato for double chorus speculated to be an early but abandoned idea for the "Hosanna" fugue.
5) [MIDI] Two 1783 sketches for a "Dona nobis pacem" fugue to close the Agnus Dei.
6) 'Solfeggio No. 2 in F' - A composition for wordless voice and keyboard accompaniment which is clearly an early version of the solo soprano part in the Great Mass's Kyrie. Likely written as vocal practice for Constanze who sang as the first soprano at the Salzburg premiere - likely composed 1782. Performed by Sabine Devieilhe.

Several other sketches formerly thought to have been associated with the Great Mass (KV 417B, 2-4) have not been included as contemporary scholarship has demonstrated they were written over a decade before the mass was even conceived of.