Wolfgang Amadeus Mozart String Quartets. Finally, the time has come: over the next few years all of Mozart’s 26 string quartets will be published by Henle in an Urtext edition of both score and parts. We begin with what are, chronologically speaking, the final four quartets: the so-called “Hoffmeister” Quartet, K. 499, and the three “Prussian” Quartets K. 575, 589 and 590. It is possible that the impulse behind the composition of these last three works was the Prussian King Friedrich Wilhelm II,