Cindy Crawford may have been the valedictorian of her high school class, but the words "dumb" and "model" tend to slide together as naturally as "peas" and "carrots." Some people, in fact, think the phrase "dumb model" is redundant. Then what is Laura Benanti, one of the quickest studies whom I've ever visited backstage, doing playing the model Candela in Women on the Verge of a Nervous Breakdown?

"It's a myth that you have to be dumb to play dumb," Benanti said the other evening, as she sat in her dressing room, fixing her hair and applying her makeup before a performance. "Just as you have to be unfocused to play someone unfocused. It's the reverse, in both cases. Otherwise, you'll have a harder time making clear the diversions."

It's a mark of Benanti's persuasiveness that I didn't mention the contrary doesn't seem to hold true: a director wouldn't cast someone simple to play Einstein or Stephen Hawking. Benanti's persuasiveness onstage, from her Tony-winning performance in Gypsy to her vivid performance in the LCT production of Sarah Ruhl's In the Next Room (or the vibrator play) to her Candela every night at the Belasco, has been among the actress's many qualities singled out for praise.

I do not, in fact, remember reading a single review of Women on the Verge of a Nervous Breakdown that didn't gush over Benanti's big Act One song, "Model Behavior." It's a non-stop number that hurtles through changes of setting. How does the actress accomplish it eight times a week? "I'll be honest. When we first started previews I had to get used to doing it. It's like jogging: the first few times you run you say to yourself, 'I'm going to die.' Then it gets better."

The number's costume changes cause me to ask Benanti: why do so many musicals have songs where people are changing their attire? "Clothing is an easy metaphor," she replied, "for change of emotion or feeling or situation." And has Benanti had to perform anything like "Model Behavior" before? "Don't forget the 'Strip' from Gypsy," she answered, with a smile. "Apparently, there's a clause now in my contract that requires me to take off at least a few of my clothes."

Does Candela define herself as a professional clotheshorse? "I don't think so," Benanti said. "My subtext for her is that she thinks she's primarily a hand model. That allows her - in her mind - not to have to obsess too much about being attractive. She thinks she's got more on the ball than that. She likes it when Pepa says to her, 'You are the smartest model I know.'"

As a song, "Model Behavior" cuts such a deep groove that I can't end my dressing-room session without asking Benanti whether she's ever able to drive the melody, or the show's score in general, from her brain. "When I'm learning something, it stays with me all the time," she replied. "I'll dream my songs, and even wake up singing them aloud." She added: "But now that we're into the run, the music isn't with me as much. When I leave the theater I can forget it and just go about my daily life."

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