One of the reviewers of Christopher Durang's new play called the character Spike "an imbecilic Adonis," which struck me as pretty harsh: the character has landed himself a movie star, Masha, as a girlfriend, which requires at least shrewdness if not perfect scores on the SAT. But this week when I interviewed Billy Magnussen, who plays Spike, he wasn't averse to discussing the notion that his guy is a dim bulb. 

"He's a bull in a china shop," Magnussen said. "And the fact that his frame of reference is so different from that of the other characters makes him seem stupid. But if you plopped Sonia or Vanya down among a group of Spike's friends then they would seem the slow ones." 

If Spike is behind the beat within the play then that doesn't make him easier to interpret than the other characters. "It's hard to play dumb," Magnussen said. "You can't be stupid to play stupid, just as you can't be drunk to play drunk. Among all the other risks, you might forget your lines." 

Magnussen tends to see Spike as free from cares rather than free from cultural awareness. "He's always happy, and always in his own world. He's going through life like a balloon drifting anywhere the wind blows him." Magnussen added: "He wants to be an actor, but if he did get a part on a TV show he'd have only one line. Something like 'Here's your coffee, sir,' which he'd rehearse for days and days to get right." 

Magnussen's life has considerably more focus than that of Spike. He grew up in Queens, New York, and in Georgia, where he was a jock. During a high-school wrestling match he ripped a hamstring. "That meant that I couldn't take gym class," the actor said, "so one of my teachers said I should take an acting class instead." That's where the girls were, so I thought I'd give it a try." 

He went to the University of North Carolina School of the Arts, and eventually came to New York, where he made his Broadway debut in "The Ritz." Film and TV work has followed: last month, he appeared in the HBO series "Boardwalk Empire," where his character met a gruesome death in a bathtub. Magnussen said that doing that scene - the show shoots mainly at the Steiner Studios, in Brooklyn - was scary. "I was told to stay under water as long as I could. And to keep my eyes open. We shot a few angles. Probably did 6 or 7 takes. Not easy." 

In between appearing in TV shows and performing in "Vanya" eight times a week Magnussen rehearses and plays in a rock band called Reserved For Rondee. "We're almost two years old," the actor told me, "and we're good." He plays rhythm guitar and synthesizer in this five-guy group, which recently had a gig at The Saint, in Asbury Park, New Jersey. "We all write songs for the band," Magnussen said, and when asked to name the rock gods who inspire him, answered, "Everyone in Led Zep." To follow the band, log on to their Facebook page: I've written this entire blog posting while their songs were cranked up on my computer. I rarely work with music playing, so for me that's high praise. 

Brendan Lemon is the American theater critic for the Financial Times and the editor of