The first four piano concertos by Mozart are now known to be orchestrations of sonatas by various German virtuosi. By using movements from the sonatas of other composers, the young Mozart seems to have begun to learn how to cope with the structural problems of composing in the piano concerto form. The concerto is scored for strings, piano (or harpsichord), and pairs of oboes and horns, as above. The first and third movements are from Raupach's Op. 1, no. 1, whilst the slow movement is based on the opening movement of Johann Schobert's Op. 17, no. 2, a composer admired by Mozart.
