“All the things I can do best and love the most” is how Byron Schenkman describes his new chamber-music series, which debuts Sunday. For the keyboardist, that means five concerts devoted to Bach, Vivaldi, Rameau, Schubert, and, first up, Beethoven.

Looking beyond the standard repertory, Schenkman is playing three rarely heard piano quartets written when the composer was 14 years old: ”ADD pieces,” he calls them, full of nose-thumbing oddnesses like the joke at the rousing end of the D-major quartet, where Beethoven asks the pianist to end two bars before the strings in a way that sounds like he’s lost his place—a written-out “mistake.”

For two decades a vital member of Seattle’s early-music scene, Schenkman is bringing in friends (not only locals, but musicians from San Francisco, Colorado, and Boston) for the series—part of a busy fall schedule that’ll take him out to New York and Connecticut and back to Portland before joining Cornish’s Gamelan Pacifica for an intriguing December concert exploring the similiarities between baroque and Javanese music. Benaroya Recital Hall, Third Ave. and Union St., 215-4747, byronschenkman.com. $10–$42. 7 p.m. Sun., Oct. 6.