You’re A Good Man, Charlie Brown, One Theatre Company, at the Athenaeum Theatre. Director Joshua Solomon and his young cast deliver a clean, simple staging of the 1999 revision of Clark M. Gesner’s musical based on Charles M. Schulz’s Peanuts. The updated book and score include two new songs by Andrew Lippa, among them “My New Philosophy,” a showcase for Charlie Brown’s cheeky little sister, Sally, who wasn’t part of the original show.

Running around a Crayola-colored playground, Lucy fights Linus for his security blanket and swoons on Schroeder’s tiny piano while Sally equates a lost ice cream cone with Shakespearean tragedy. Snoopy fights the Red Baron between meals, and Charlie Brown faces one disappointment after another–a stalled kite, a blown baseball game, the oblivious little red-haired girl. The actors capture their characters’ sweetness, crabbiness, and vulnerability, keeping up a lively pace throughout.

Some do better than others, however, at their big numbers. Patrick Quinlan, Mallory Portnoy, and Cyril Watson as Charlie Brown, Lucy, and Linus hit the mark every time. But most of Adrian Briones’s lines as Schroeder were unintelligible on opening night, and though Adrianne Blanks is cute as Sally, she shrank back during the “Philosophy” solo. Diego Colon as Snoopy has terrific comic timing and a lovely tenor voice, but he was so smug in his adorableness that he coasted through “Suppertime,” which should have been a showstopper. These aren’t fatal flaws, however, and overall this is a well-executed bit of summer fluff.