The piece
Born in Germany, Friedrich Kuhlau settled in Copenhagen in 1810 and lived there until his death. His sonatinas, the three of Op. 20 among them, extend the classical style with a wealth of scales and arpeggios. This first movement unfolds a C major theme that climbs the triad over an Alberti bass, passes through a stormier episode in C minor, then returns to the brightness of the opening.
The Alberti bass, C-G-E-G in eighth notes, starts out written in the treble clef and runs at about four notes per second. The thumb strikes the repeated G: keep it light so you hear the harmony rather than that one note. In the right hand, the sixteenth-note scales reach eight notes per second; settle your fingerings and raise the tempo in stages, which is exactly what Noctave's reduced tempo is for. In the minor episode the left hand drops into low octaves, 23 in all, under right-hand triplets. The range, from a low B to a high C, and the length, nearly four minutes, call for stamina.