Sinfonia Concertante for Violin, Viola, Cello and Orchestra (Mozart)

The Sinfonia Concertante for Violin, Viola, Cello and Orchestra in A major, K.Anh 104 (320e), is an incomplete composition by Wolfgang Amadeus Mozart
Background.
Mozart is believed to have started work on this concerto around the same time as the Sinfonia Concertante in E-flat major K. 364. For unknown reasons Mozart abandoned the work after writing 134 bars of the opening movement.
Structure.
As completed the work consists of a single movement "Allegro".
Completions.
Several composers have completed the movement. Around 1870, Otto Bach composed a completion which Dennis Pajot described as having a very obvious join between the part written by Mozart and the part written by Bach. In 1969, Robert D. Levin wrote a completion that was more sympathetic to the surviving material. More recently, composer Hans Ueckert announced he was working on a completion for the Octava Chamber Orchestra. Another composer to have made a completion is Philip Wilby.
Another completion was made by Italian Composer Alessandro Solbiati for I Solisti Aquilani and played first time in Rotterdam during International Viola Congress 2018 (Soloists: Daniele Orlando, Violin – Gianluca Saggini, Viola – Giulio Ferretti, Violoncello).