No chamber-music genre was honored with so many works as Mozart's duos for piano and violin. As well as the 16 sonatas they include two variation cycles which Mozart composed in 1781, thus in his first Viennese year, and were most likely intended for his various pupils and students.
The combination of duo/duet and variation was to make the two works especially well known. Both cycles, especially the second one in g minor, are finest Mozart.