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.

British composer Philip Wilby, who completed the movement in 1989, notes similarities between K. Anh. 104 and its counterpart, K. 364. He mentions scoring similarities (in fact, they both share the exact same orchestration), the tuning of the viola, similar passages and rhythmic patterns. Wilby's reconstruction of the work is substantially based on the opening movement of K. 364.

He also notes the experimental writing of the cello part, and that this work holds a historical importance within Mozart's output; the fact that it is his only writing for solo cello and orchestra known as of present, with a lost Cello Concerto in F major, K. 206a still being documented in the composer's catalogue, and a possibility of it being discovered in the future. The cello part also employs Jean-Louis Duport's newly introduced technique of using the thumb in order to reach higher registers (as the work contains a very demanding rising figure to a G-sharp from the bass within the course of a single bar).