The Divertimento in E♭ major, K. 563, is a string trio, written by Wolfgang Amadeus Mozart in 1788, the year in which he completed his last three symphonies (nos.
[1][2] The work was completed in Vienna on 27 September 1788 and is dedicated to Michael von Puchberg, a friend and fellow Freemason, who lent money to Mozart.
As Alfred Einstein wrote in Mozart: His Character, His Work (and as excerpted in the notes to a Kennedy Center performance), Mozart's only completed string trio shares with most divertimenti this six-movement format, but from that no lightness of tone should be understood – rather, "it is a true chamber-music work, and grew to such large proportions only because it was intended to offer ... something special in the way of art, invention, and good spirits.
Tully Potter, in his notes to a recording, reports that when the Philharmonic String Trio of London performed the work in 1936, "that pompous old Wagnerian Ernest Newman reported that 'the work is over-long, and some of it mere music-spinning of the conventional eighteenth-century type'.
Mozart's Divertimento in E♭ major is "one of a kind", according to the notes to an Emerson String Quartet performance.