The keyboard was an enduring focus of Haydn's activity and achievement. Composition began for him with improvisation at the keyboard, and he later likened himself to “a living keyboard” touched by imagination. As a performer he was by his own admission no “wizard”; yet he mastered the harpsichord and clavichord in his youth, and skillfully navigated the passage to the fortepiano as it became increasingly available in the 1780s. These three instruments inspired around sixty solo sonatas (Hoboken work-group XVI), a handful of incidental pieces (Hob. XVII), at least forty keyboard trios with violin and cello (Hob. XV), and an odd dozen divertimentos and concertinos for keyboard and accompanying strings (Hob. XIV). This impressive body of work runs the gamut from the solo and accompanied Clavier divertimentos and partitas of the 1750s and early 1760s to the London pianoforte sonatas and trios of 1794–95, bringing him from the loneliness of his attic garret on the Michaeler-platz to a pan-European market. This essay examines how Haydn's keyboard music – while remaining essentially a vehicle for private sentiment – widened its appeal to reach an international audience of publishers and patrons.