Fantasy in c (fragment) for violin and clavier, edited and completed as a Clavier piece by Maximilian Stadler

The numerous individual pieces for one keyboard instrument (under which also the few pieces for glass harmonica and mechanical instruments may be subsumed) belong to different traditions and consequently display great variety. The largest group, consisting of almost 60 pieces, dates from Mozart’s youth. A large number of Mozart’s keyboard pieces was entered by Leopold Mozart in the music book he had originally set up for the keyboard lessons of his daughter Maria Anna. These are Mozart’s earliest works. Wolfgang was unable to write down the compositions himself until he was eight years old. At that time, in 1764, while the family was in England and his father severely ill, Mozart filled the so-called London Music Book with 42 piano pieces (KV 15a–15ss).

Some of Mozart’s keyboard pieces are notated fantasies, and there are also several rondo movements, especially from the Vienna years. Keyboard reductions of dances for ensemble need to be mentioned in this context, as well.

During his final years, Mozart was commissioned to write several pieces for sophisticated mechanical organs in the so-called Müller’sches Kunst-Kabinett (KV 594, KV 608, and KV 616). These were distributed in print only in keyboard arrangements, usually for piano four-hands.