Mozart: Two Duets, KV 423 and 424
Mozart's duos for violin and viola, arranged for flute and alto flute by Barbara Hill and published by Edition Kossack.

The story of the duets
The two duos KV 423 and 424 for violin and viola were composed by Wolfgang Amadeus Mozart during a visit to Salzburg in 1783. They were part of a set of six duos which Michael Haydn, younger brother of Joseph Haydn, had been commissioned to compose for the Archbishop of Salzburg. Because of a serious illness Michael Haydn only managed to complete four of the six, and for this delay he was threatened with the forfeiture of his composition fee.
Mozart, a good friend of Haydn, visited him daily while in Salzburg and helped him out of this difficult situation by composing the remaining two duos for him. They were handed in as part of the set under Michael Haydn's name, and the Archbishop did not detect in them the obvious signs of Mozart's unique style and skill.
Some years later Mozart asked for the duos to be returned to him; whether as a copy or as his original manuscript is unknown. In 1792, only a few months after his death, the first edition was published. Possibly this was instigated by Mozart himself, but there is no proof.
The arrangement
In the Duetto secondo KV 424 both instruments are treated as equal partners, resulting in a musical dialogue throughout the work which was stylistically unusual at that time.
Among the various editions of the Mozart violin and viola duos, a facsimile of the original manuscript was also used as a basis and reference for this arrangement for flute and alto flute.
“…impresses as if it were originally composed for flutes. A real enrichment to the flute repertoire.”
„Das Werk scheint für diese Besetzung geradezu geschaffen zu sein und ist somit eine echte Bereicherung des Repertoires.“