String Quartet No. 15 in D minor, K. 421/417b (Op. 10, No. 2)

4 movements

Wolfgang Amadeus Mozart · 1783 · D minor · 426 bars · 399 chords analysed

The only one of the “Haydn” quartets in a minor key, reportedly written while Mozart's wife was in labour in the next room.

Mozart's 23 quartets include the six he dedicated to Haydn in 1785 — the fruit, he wrote, of “long and laborious effort” — and the three “Prussian” quartets written for a cello-playing king.

Keys visited: D minor, F major, E♭ major, A minor, C minor, A♭ major, C major, D major.