Being that Schubert was suffering great mental and physical anguish at the time of his Octet’s completion in 1824, it’s surprising that the work is so sunny and optimistic. At a little over an hour, it’s the Austrian composer’s longest chamber work—and his most inspired. With just eight instruments, Schubert crafts an opening movement on the scale of a Beethoven symphony, ideas ricocheting between strings and woodwind, bass and treble. The “Adagio” is a sublime song for clarinet that rivals Mozart for its understated beauty while an ebullient central scherzo, stately variations, and suave minuetto culminate in a finale of intense drama that seems to glance toward Wagner. It’s all stunningly recorded and performed, too—a benchmark performance full of wit, passion and charm.