Initially subtitled “Pierrot is angry at the moon,” the Sonata for Cello and Piano does have some of the modern-day commedia dell’arte sensibility—a raw, heart-on-the-sleeve, dark humor. The Cello Sonata is the most unrefined, emotionally exposed of Debussy’s three sonatas—maybe even of all his works. The opening movement lays out a singing theme in the cello, by turns churning up ecstatic outbursts and quiescent moans. The middle movement is almost jazz-like in its counterpoint among three voices—piano in a dual role of melodic partner with the cello and as plucky, bluesy accompaniment, bowed cello in its upper register sharing the melody with piano, and the cello’s lowest notes, played pizzicato in an elastic syncopation that takes on the role of an upright jazz bass. There is indeed a lunar quality about this movement: Time stops and starts, melodic and harmonic themes shift between sultry darkness and starlit dances. From the final quiet statement of the serenade spills an exultant duet between cello and piano. The cello’s opening ascending sequence introduces a dancing theme that is folded into the mix for the rondo-like reexamination of the work’s previous themes. —Meg Ryan