Piano Concerto No. 21 in C Major

Mozart was a new kind of keyboard virtuoso, more concerned about the quality of a player’s musical insights and the sound they created than the speed they could play at. “It is far easier to play a thing quicker than slower,” he wrote to his father, Leopold, “but is this genuine music?” As if in response to his rhetorical question, during the whirlwind February and early March of 1785—which included performing a dozen concerts and enjoying an initial play-through with Haydn of the string quartets he intended dedicating to him—Mozart somehow found time to compose his Piano Concerto No. 21 in C major, K. 467, finished just in time for the premiere on March 10. The opening “Allegro maestoso” finds Mozart playing with the conventions of martial music—it opens almost imperceptibly, and then the piano’s very first entry teasingly delays the return of the marching main theme—while the finale takes us to the lively world of opera buffa. In between comes a dreamy “Andante” that floats an exquisite melody over wave upon wave of gently pulsating triplets.