“I want to show you now what happens when I put baggy pants on,” actor and clown Bill Irwin, OC ’73, told the Finney Chapel audience Sunday night. He’d taken the stage in an old-fashioned but safe ensemble of a white shirt and loose gray pants — the only thing unusual about his appearance was a brown fedora — but that would change over the course of the night. Once Irwin donned the baggy pants (and later, the even baggier pants), everything became fair game, from classic clowning to dramatic monologues to musical comedy.

Toward the beginning of the show, Irwin, who spent the year after he graduated from Oberlin at Ringling Brothers and Barnum & Bailey Clown College, declared that half of physical comedy is finding a problem. To demonstrate the potential humor of “getting into trouble,” he thrust his hands deep into his pockets and found himself incapable of removing them. He tugged at his pockets as if there were chewing gum inside, fusing to his hands. As with most physical comedy, it was funnier than it seems on paper, and Irwin’s jerky, increasingly frantic movements were greeted with shrieks of laughter.

That’s not to imply that Irwin’s humor was lowbrow. In a segment of musical comedy that Irwin said was “created withOberlin in mind,” Irwin, donning a straw boater’s cap, pulled out a comically tiny ukulele and launched into a gasping, neurotic ditty he called the “Querulous Cartesian Love Song” — whatever that means. Then his attention turned to the art of clowncraft. Slipping on, in true Oberlin style, a pair of black thick-rimmed glasses, Irwin announced, “In physical comedy, you’re often treating your pelvis as you don’t in normal life.” By tilting his brown fedora in different directions on his head, he demonstrated how much such small details could shape a character. Then his attention returned to the pelvisas he carefully modulated his center of gravity to instantly morph into different characters with distinctive mannerisms.

Irwin, always eager to keep the show moving, never stayed with one bit for long. Directly after his segment on techniques of physical comedy he segued into a long explanation of his love for Irish playwright Samuel Beckett. In the 2009 Broadway revival of Beckett’s classic Waiting for Godot, Irwin played Vladimir, but instead of a monologue from that play, he delivered a frantic, dynamic performance of an excerpt from Beckett’s Stories and Texts for Nothing. This section, while fascinating to watch, was one of the few missteps of the show. Irwin had assured the under-12 members of the crowd that the monologue would be short, but, regardless of age, the audience wouldn’t have complained if it had been shorter.

He had greater success with his next dramatic foray. Reprising the role for which he won a Tony Award in 2005, Irwin performed a scene as George from Edward Albee’s Who’s Afraid of Virginia Woolf, supported by College senior Colin Wulff as husband, Nick. Wulff held his own admirably, but Irwin was bewitching to watch, inhabiting his character completely and conveying his bitterness without allowing the character to fall flat.

Then, of course, on to the next thing. Irwin freewheeled energetically through a demonstration of how percussion cues can supplement a physical performance, with drum cues supplied by a game College junior Dan Bloch, who, according to Irwin, had been recruited a mere three hours before. The baggy pants weren’t done for the night, though. In a lengthy segment weighed down with backstory, Irwin donned progressively huger pairs right on top of the other, clowning for a little at each stage to Bloch’s drum cues. At last count, Irwin had four pairs of pants on at once.

He added a white vest, red jacket with tails, a black wig and the requisite pair of glasses outfitted with a rubber nose and fake mustache. He then began an elaborate pantomime of a man who has a good deal of trouble with his spaghetti at a picnic lunch. It was broad humor, of course, but delightfully so, to watch Irwin chase an errant noodle around the stage.

Irwin was the consummate performer, able to bring out the best of any medium he tried. Those in the audience who came anticipating a pure clown show certainly got their fill, but Irwin proved that he has more range than that. He’s as comfortable with Samuel Beckett as with a rubber nose — and just wait and see what happens when he gets ahold of some baggy pants.