The first work Mozart entered in the thematic catalogue he began on 9 February 1784 and kept until his death; it therefore opens the only complete record of his output in his own hand. He wrote it for Barbara Ployer, a pupil and the daughter of the Salzburg court's agent in Vienna, who played it at her father's house in Döbling. Mozart noted that the wind parts were optional and that the concerto could be given a quattro, with strings alone — a practical concession that has kept it in chamber-sized programmes ever since.