Autograph manuscript of the Piano Trio in one movement WoO 39
Maximiliane Brentano, the musical daughter of Franz and Antonie Brentano, was not yet ten when Beethoven composed his Piano Trio in one movement WoO 39 for her "to encourage her piano playing". The score is unusually cleanly written; it could be used for performance. Beethoven added fingerings to the piano part for ease of playing. No other Beethoven manuscript contains such extensive fingerings. The encouragement seems to have paid off. Nine years later Beethoven dedicated his Piano Sonata op. 109 to the adult Maximiliane Brentano.