In the summer of 1783 Mozart was a regular visitor to the home of Johann Michael Haydn (brother of the great Franz Joseph) in Salzburg, as Michael was convalescing from a serious illness. Michael Haydn was at risk of having his salary cut off as a commission for string duets from his patron, Archbishop Hieronymus Colleredo, was at the same time going unwritten due to the composer’s illness. Mozart, hearing about this, took the task upon himself, and completed two “forgeries” (this duo, and that in B flat major K.424) which Michael Haydn presented as his own. Although disguised in places to be able to be passed off as the work of J.M.Haydn, whose work Mozart greatly respected, these two fine and virtuosic duets are still distinctly Mozartian.