It was during his stay in Mannheim between October 1777 and March 1778 that Mozart received commissions for two string quartets with flute (K. 285 and K. 285a), an instrument that was in vogue at the time, likely because Prince-Elector Karl Theodor of Bavaria played the flute as an amateur in the capital of the Palatinate. A graphological study indicates that the quartet K. 285b was likely composed in 1786-87 in Vienna These works hold a special place in Anna Besson's heart, as the flutist performed them during one of her very first concerts on tour at the age of fifteen She was keen to include Hoffmeister's arrangement of sonata K311 'for the beauty of it's central movement and the extreme delicacy with which the publisher, a great friend of Mozart's, took the two hands of the keyboard and gracefully redistributed them between the flute and the strings.'