Fantasia No. 3 (Mozart)

Fantasia No. 3 in D minor, K. 397/385g ("Fantasy" in English, "Fantasie" in German) is a piece of music for solo piano composed by Wolfgang Amadeus Mozart in 1782. Despite being unfinished at Mozart's death, the piece is nonetheless one of his more popular compositions for the piano.
The original manuscript has not survived and the final measures of the piece have been lost or were never completed by Mozart. The ending as it currently exists (the last 10 measures) is believed to have been written by August Eberhard Müller, one of the composer's admirers. For her Philips Records recording, pianist Mitsuko Uchida has written her own ending that is similar to the piece's beginning, rather than using Müller's.
Structure.
The "Fantasia" runs to just over 100 measures, in a single multi-tempo movement marked "Andante – Adagio – Presto – Tempo primo – Presto – Tempo primo – Allegretto", and a full performance takes approximately five minutes.
The Austrian composer and academic Gerhard Präsent has published an extensive analysis of the "Fantasia" that reveals highly interesting structural correlations between the different parts of the composition. He has also made an arrangement for string quartet in four movements, called the "Fantasy Quartet in D", in which this piece is the first movement.