A concerto for two pianos composed during his Salzburg period. Its year of composition is generally considered to be 1779 (or 1780), after his trip to Mannheim and Paris, but some theories, based on the quality of the paper used, suggest 1775-77. The premiere is unknown, but it was subsequently performed in Vienna at least twice, including private occasions.

This brilliant and splendid concerto in E-flat major is presumed to have been composed for performance with his sister, Nannerl. The two pianos play an equally prominent role, either in unison or by sharing the melody, but particularly noteworthy is their frequent movement in parallel thirds. Naturally, a highly coordinated performance is required.

Cadenzas by Mozart himself for the first and third movements have been preserved.

First Movement: Allegro, E-flat major, 4/4 time. Concerto-sonata form.

Continuous sixteenth-note figures create a brilliant and lively atmosphere throughout. The two pianos announce their entrance with a four-octave unison trill.

Second Movement: Andante, B-flat major, 3/4 time.

A slow movement primarily developed by the two pianos.

Third Movement: Rondo. Allegro, E-flat major, 2/4 time. Rondo form.

A movement with a cheerful and approachable rondo theme. In this movement, the two pianos frequently play different figures simultaneously, creating a breadth suitable for a finale.