The amazing variety that Mozart compressed into the ten minutes of this work is remarkable even by his standards. The piece opens with a recitative for voice and strings, the winds and piano not making their entrances until the rondo, followed by the piano asserting itself with eight solo measures before the voice re-enters.
Alfred Einstein noted of this composition that “Mozart poured into it his whole soul… We have the impression that [he] wanted to preserve the memory of the performer’s voice… not suited to a display of virtuosity, but full of warmth and tenderness; and that he wanted to leave with her in the piano part a souvenir of the taste and depth of his playing, and of the depth of his feeling for her…”
The reference to “her” is a reference to singer Nancy Storace who was visiting the place where Mozart was located at the time.
Here is pianist Helene Grimaud to participate in this extraordinary composition: