In his lifetime, A. F. Doppler (1821 - 1883) was a famous composer and solo player. The performances in which he played duets with his brother Karl, also a flutist, made them famous all over Europe. Quite contrary to the arrangement custom of the time, the paraphrase presented here is based on a comparatively unknown piece: Franz Schubert's opera "The Conspirators" (also called "Marital Row") had only been performed once during his lifetime in private, having only a piano for accompaniment. It must have been the clear-cut melodies which inspired Doppler to this work. Due to its virtuosity, it is suited for rather advanced flute duets.
Difficulty level, roughly compared to ABRSM exam grades. 0 is beginner, 9 is advanced (beyond grade 8).