Max Gutbrod, flute
The author is another of those composers about whom little and not even a portrait is available over internet, so one can imagine how this piece “for amateurs” came about. Keller took short elements of a melody with a comparatively strong harmonic focus as a basis for extensive variations, that allowed him to expand on this melody and varied this melody into many similar forms, including many varied elements and speeds in a considerable number. I find this to be similar and, at the same time, forming an impressive contrast with the another virtuoso piece:
https://www.youtube.com/watch?v=MTHggI5mMfo.