The Stamford Center for the Arts and The Palace Theatre presents 42nd Street. As the curtain raises, the audience sees at least 100 legs banging out the intricate yet massive beats. When the curtain goes all the way up, the audiences’ eyes pick one fellow in the crowd to follow as he leads the “Audition” for the newest Julian March ’30s musical extravaganza. The star-is-born character is Peggy Sawyer from Allentown, Pa., who stumbles into the chorus and, when the diva Dorothy Brock breaks her foot, just has to go out there and do it for every speck of stardust on Broadway. Peggy, the ingénue, looks demure from the knees up. Down in her tap shoes, she explodes with the abandon that only immaculate precision can justify. When her romantic lead, Billy Lawlor, tells her, “You’re a looker, you can chirp like a bird and you’re pretty darn good in the hoofer department,” the audience darn well trusts him.