When Mozart returned to Vienna in late November 1783, he entered into the busiest and most successful years of his life. He performed and conducted a substantial number of his own compositions, and in addition to public performances he was also in great demand for private concerts.

In March 1784 alone he played 13 times, mostly at the houses of Count Johann Esterházy and the Russian ambassador, Prince Golitsïn. As he writes to his father on 12 June 1784, “Tomorrow Herr Ployer has a concert in the country, at Döbling, where Mdlle. Babette is to play my new concerto in G, and I the quintet with wind instruments, and then we are both to play the grand sonata for two pianos.” Mozart was eager to bring along the composers Paisiello and Sarti so that they could firsthand hear the performance by his student Babette Keglevich. In the event, both composers were unable to attend.

But Mozart had other things on his mind as well. He had recommended the violinist Menzl for a vacant position as leader of the Salzburg court orchestra to Gottfried Ignaz Ployer. Ployer, who was hosting the concert, was also the agent of the Salzburg court in Vienna and father of Mozart’s student Barbara. Mozart had previously written, “I confidentially recommended Menzl to Ployer, a handsome, young, and skilled musician. He is now awaiting a decision and will surely get his 400 gulden and a new suit. I already scolded Menzl about asking for a new suit—it’s so beggarly.” Menzl wasn’t shy trumpeting his upcoming Salzburg appointment, and Mozart eventually found out that he had also kept the fact that he was married a secret. Mozart was flabbergasted and wrote, “Menzl is, and always will be, an ass.” In the very same letter Mozart also announced that he had given the publishers Artaria and Toricella a number of piano sonatas, and that he was planning to publish a number of symphonies as well. And by the way, the quintet announced in this letter is the glorious K. 452 for piano and wind instruments.