Few knew her name before she was announced for the title role in the stage version of the daffy film musical. Only weeks after the April 18, 2002, opening of the show and knocking audiences into the aisles with a belt voice that shook the rafters, she won the 2002 Tony Award for Best Actress in a Musical.

Her prior work included stints in Les Misérables, Grease! and the Broadway revival of Annie, among other shows on tour and in New York. Did anyone suspect the anonymous college-age girl who toured in the chorus of The Will Rogers Follies would land so well?

Internet message boards lit up with the question: Has this generation seen a vocal performance as big and rich and funny as the one Foster gave? People compared her to Carol Burnett — a touching comedienne with pipes.

The casting of Foster in the musical by lyricist-librettist Dick Scanlan and composer Jeanine Tesori almost didn't happen. In 2000, Foster was the role's understudy during a regional test run at the La Jolla Playhouse in California. Just before previews, Erin Dilly, who was cast as Millie, was out sick for several days, so Foster went into tech rehearsals with script in hand.

The show's commercial producers were in town and caught Foster's performance. A change in casting was made – and so was Broadway history. "Erin and I have such a history together and there's no animosity between us," Foster said days before her Feb. 15 final performance (which is also Delta Burke's final show as Mrs. Meers) at the Marquis Theatre. "I think Erin is brilliant, one of the most talented actresses I know."

Foster, who worked with Dilly when they were child actresses in metro Detroit, explained, "I always say it's sort of like the universe took over and in three days everything changed. On the third day of rehearsals we did a full run through of the show, and I had learned the whole show and was able to do it off-book. I thought, I gotta learn to do it eventually [as the understudy]. Producers were there."

On the fourth day, she was preparing to go back into the ensemble when director Michael Mayer called and said the part was hers if she wanted it. "And I burst into tears and cried for about four hours because I was so confused and I didn't know what had happened," Foster said. "And I was so worried about Erin. I didn't know what to do and how to handle it."

Previews for Broadway didn't begin until 2002. California is a bit of a blur, she admitted.

"It's a very different show," Foster said of Broadway. "We took a year off and the creative team would go away on little sabbaticals and write and work on the show. During that year I was meeting with them, singing new songs and working on new material."

Beyond the belting opportunities she has with such songs as "Not for the Life of Me," "Gimme, Gimme," "Forget About the Boy" and the title number, Foster shows off a distinctly comic side, twisting her long legs into pretzels in her attempt to fit into an office typing pool where she hopes to snag the handsome boss.

Did Millie give her permission to be a comic actress in a way she hadn't been?

"Absolutely," she said, but added, "I kind of grew up as that gawky, tall, skinny, frizzy-hair-and-braces girl. So in our family, growing up, I was very self-deprecating and making jokes. That was my way of dealing with life. [Millie] give s me great room to be funny. I've been able to mine the material and teach myself about comedy and timing and how to make something funny and sincere after 700 performances. Comedy is so hard."

With her dark bobbed-hair wig as Millie (nothing like her silken, lighter real hair), she resembles a young Mary Tyler Moore. And with her penchant for the physical, she recalls Carol Burnett's most athletic sketch comedy.

"I've always been such a fan of the physical comedy," Foster said. "One of the things about Millie that I've enjoyed so much is that I've been able to use my body in a way that I've never used it on stage. When I first started thinking about the character, I looked at a lot of photographs of the time period — the women's posture and stuff. And I started incorporating it. It's been fun to use my legs and my gangliness to its advantage as opposed to letting it be a detriment. It's been like two years of training, in a way."

Foster bills herself as a "quirky ingenue" rather than a character actress. "I think I have to come from a sincere point of view, and then add the quirks to that," she explained.

He next role is playing Jo March in a Broadway musical version of the beloved novel, "Little Women," come fall.

Performances of Thoroughly Modern Millie continue Feb. 16 with Susan Egan starring as Millie.