Juxtaposing early and late sonatas reveals just how much Leopold Koželuch’s style changed over a thirty-year period. The three early sonatas from the 1770s, though harmonically modest, fizz with Rococo charm and elegance. The late sonatas meanwhile were intended for a fortepiano, which had eclipsed the harpsichord, and are two-movement works. They feature bustling rondos and deft janissary devices, one of which is the buzzing effect generated by a knee lever on the original 1815 Johann Fritz instrument used in this recording.