With a strong stroke, Barbara Deppe’s cello sweeps in with a wave of sound, reveling in its sonorous tones, then gliding up clear and light in the air.

Later, comical like a slide whistle, the cello turns on a dime and holds a point of tension – one that caught the ear of the performer herself.

“This piece grabbed me when I heard it five or six years ago,” Deppe said of Debussy’s Cello Sonata.

“I said, ‘I have to play that piece.’ It’s challenging, but endlessly fun.”

Deppe will be joined by pianist Jim Quitslund in performing the piece at 4 p.m. Sunday, as part of the Mostly Music chamber music series at the Playhouse.

The concert – which also features Poulenc’s Sonata for Clarinet with clarinetist Patti Beasley, and Mahler’s Lieder eines fahrenden Gesellen, Songs of a Journeyman with baritone Joe Prater – is a summation of the season, which focused on forms popular in the 18th and 19th century. These early modern pieces use the forms innovatively.

Whereas in classical sonata form, dance-like, fast music would be saved for the Scherzo movement, with Debussy, it bursts out in the middle of any movement.

The Poulenc is a jazzy piece, which debuted in 1962 with clarinetist Benny Goodman and pianist Leonard Bernstein.

Quitslund says in interpreting the Mahler songs, he and Prater looked to the text for guidance rather than simply reveling in “rich, legato” tones as is the tendency among performers.

In places where the journeyman is bemoaning leaving town because his love is marrying another, the pair chose a sadder tone rather than the conventionally heroic way it is sung.

The Debussy is a personal favorite of Quitslund and Deppe, who performed together for the first time about 18 months ago with this very piece.

“It has such a sense of humor, as well as that Debussy shimmering feeling to it,” Deppe said. “And it’s silly in places.”

The second movement begins with the cello and piano playing bare pizzicato, reminiscent of a double bass or guitar. Other swift passages rush by in a blur.

Playing the composer’s works for the second time, Quitslund has a better understanding of him.

“(I) discovered Debussy was more of an intellectual and emotional than I had thought,” he said. “He was a critical thinker, very angry about modern problems and the defeat of France at the hands of the Prussians. And he thought music was most important in life, just as we do.”

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Denoument

Debussy’s Cello Sonata highlights the final concert of this season’s Mostly Music chamber music series, 4 p.m. April 10 at the Playhouse. Tickets are $12 each at the Playhouse, at 842-8569 or www.theplayhouse.org.