The Serenade Op. 41 is based on Beethoven's Opus 25 for flute, violin and viola. Although the version for piano and flute (or violin) did not originate from the composer ? but was probably undertaken by the composer Franz Xaver Kleinheinz. Beethoven did, however, ?look through it and substantially improve some passages?, as he assured his publishers Hoffmeister and Kühnel in September 1803.