Staying true to his local roots, pianist Jon Nakamatsu graces many local concert series in the Bay Area. Throughout the season, astonishingly, he will play with the Stanford University Orchestra, his alma mater, in multiple concerto performances for Stanford’s Beethoven Project. And this weekend, the Mill Valley Chamber Music Society hosts him for a recital of Schumann (Papillons and Carnival), Schubert Impromptus, and Beethoven’s “Moonlight” Sonata. This is an exceptional performer.