Erin Davie and Emily Padgett on the Sisterhood of Broadway's Side Show

When Erin Davie was a student at Boston Conservatory of Music, she auditioned for a leading role in the university's spring musical — Henry Krieger and Bill Russell's Side Show — and didn't get it. "I was heartbroken," says Davie, one of the lucky few who got to see the short-lived 1997 original production. But Davie, who went on to appear in Grey Gardens and A Little Night Music, got the last laugh. She currently stars in Bill Condon's revised version of Side Show at Broadway's St. James Theatre.

Make that co-stars. There are two leads in Side Show, a somewhat fictionalized bio-musical about the conjoined-twin vaudeville performers Daisy and Violet Hilton. Playing Daisy, to Davie's Violet, is Emily Padgett, a veteran of Rock of Ages and Grease, whose introduction to this material was the cast album. "I really didn't know the story of the twins," Padgett says during a pre-show conversation in her dressing room, which is conjoined with Davie's. "I feel honored, in a way. This score has touched so many people, and even people who haven't seen the show know the music."

With the advent of YouTube and other video-sharing sites, it's become much easier for theatrical fans to look back on that original mounting, which played house a few blocks away at the Richard Rodgers Theatre and made stars of its leading ladies, Emily Skinner and Alice Ripley. Davie and Padgett are well aware of that fact. "You can be daunted or just be like, 'Well, let's do what we can do,'" says Davie, who is seated on the sofa next to Padgett. The fact that the show has been extensively rewritten (or as Davie puts it, "Not your mama's Side Show") also helps. "I think vocally, it's a lot more legit soprano," says Padgett. "This show is sort of as legit as I go, and this might be as contemporary belty as Erin has done. So we meet in this great sweet spot." "I think it's the same keys, though," says Davie.

They didn't know each other before their first meeting at one of the auditions, but they jumped right in. "The material really bonds you," says Davie. "By the nature of the thing, you just become this unit." Padgett adds, "It's so cool to be able to go through an entire show with someone at your hip and be able to feel the warmth of another person's body."

It's also proved to be an intriguing learning experience. "It's a constant discussion," Padgett continues. "Everything is a compromise. I was always saying, 'Erin, what do you think about this line? How should we sing this note?' We really learned it like it was one person. We're one, though we're two." Padgett cites an example: "I'm very OCD about being early to places, and she's very laid-back. I annoy her because I'm just like, 'Let's go,' and she's like, 'We have time.' I can't go up the stairs without her, because we're together. That's one thing you have to learn." "No one would ever think about that unless you're in this situation," says Davie. "You have to be open and pliant."

Davie and Padgett went right to the source to research their characters. "We met with a friend whose grandfather was one of [the Hilton sisters'] dancers," says Padgett. "He's got amazing photographs and a lot of stories. He compiled a ledger of all their performances. They performed almost every single day in that span of time when they were in vaudeville."

Padgett's voice strikes a tone of admiration when talking about how independent the Hilton sisters were. "They were masters of self-promotion. They would take little pennies and drop them in town and kids would pick them up and follow them to the show. They would do twin day, where they'd come into the town and take a big photograph with all of the twins in town. They were very smart businesswomen. We walked away feeling that they had a really fabulous life."

The independence of the Hiltons is what impresses Davie, and she's even more impressed that Side Show is one of the few musicals currently on Broadway with two strong female characters as its leads. "They assert their independence and their personal power at the end of the show in such a beautiful way," says Davie. "So not only are they lovely roles, it's how much they grow. Whoever's out there reading this who writes, write more. It really touches people, especially girls."