This lecture was followed by a surprise: a musical event featuring Paul Einstein on violin and Siegfried Räbblen on Piano. Paul, a great grandson of Einstein's is a musician living in the south of France and played on Einstein's violin. The piece was a Mozart Sonata, K304, written in 1778. It is the only instrumental work Mozart wrote in E-minor and its poignancy reflects Mozart's reaction to the news of his mother's death. It was Einstein's favorite.
So I looked it up and found this flute performance of k304 by Ginevra Petrucci and really liked it, and bought the score complete with accompaniment CD. Which turned out to be unnecessary, because as it happened, my flute teacher had just completed her own flute adaptation of the piece. So I worked my way through both movements of her version and am now reasonably happy with my playing, although there are always lots of things left to improve at a later point.
By the way, I don't think it required much virtuosity from Einstein or other amateur violinists to play it - I noticed one could readily play it unchanged on viola i.e. even without the violin's E string, and thus also on cello an octave below. So, if you have a string instrument sitting around, give it a try and release your inner Einstein.
Oh, and for flautists it is of course interesting because it is quite close in time (as well as in the Koechel Verzeichnis) to the two flute concertos.
Next up: a Telemann fantasia ...