Composed 1772; 12 minutes 

Until his early twenties, Mozart was better known as a touring prodigy than as a composer. On his early concert tours, he performed his own music when possible, mostly improvisations, solo sonatas and sets of variations. His sister Nannerl, a gifted pianist in her own right, later wrote to the publisher Breitkopf & Härtel mentioning several four-hand sonatas composed during their childhood for the two of them to play on their tours. Only one of these early works survives (K. 19a).

K. 381, composed when Mozart was 16, is the earliest of four surviving duet sonatas from his maturity. It’s tempting to imagine it written for home use—for Mozart and Nannerl together, as in the family painting, or perhaps for teaching purposes. Either way, it is a delightful sonata, with extrovert outer movements drawing on the early Italian symphonic manner that Mozart would have heard while traveling, and a lyrical, sustained cantilena throughout the middle movement.