Leonard Bernstein sat hour after hour in the rear of a darkened theater as a parade of singers and dancers anxiously auditioned. At the end of one tryout, the composer suddenly rose and applauded. "Sing A Boy like That," he commanded the lithe young black woman on stage. "Hey, Mr. Bernstein," Debbie Allen shot back in her best put-on Puerto Rican accent, "I don't know that song, but if you give me the job, I can learn anything." Bernstein told her to learn Anita's songs in West Side Story.

When the revival of the 1957 musical opened on Broadway last month, the critics agreed that Allen is indeed a quick study. She rivaled Chita Rivera (the original stage Anita) in sexiness and sass, and night after night her rendition of (I like to be in) America steals the show.

For Allen, 27, it's the latest peak in a career that has also suffered the pits. Her big TV shot in NBC's 3 Girls 3 got great notices but ran only 13 weeks. Undaunted, she kept on plugging and played Alex Haley's wife in Roots II. Her Broadway fortune has been equally uneven. While an understudy in Raisin, she filled in for Shezwae Powell one day and aced her out of the show. But when stardom finally loomed with the title role in Alice, a musical adaptation of the Lewis Carroll classic, the show died out of town. "Down the rabbit hatch," wails Allen. True to form, she hopped up again six months later in the Fats Waller revue Ain't Misbehavin'.

The daughter of Andrew Allen, a Houston dentist, and Vivian Ayers, an artist and art center director, she was the youngest of three talented offspring. Her brother, Tex, is a jazz musician in New York and her sister, Phylicia, is a singer and actress married to Victor Willis, former lead singer of the Village People. Their parents divorced in 1957, and Debbie and her mother struggled together to overcome the frustrations of being talented and black in Texas in the early 1960s. Barred from the Houston Ballet Foundation at 8 because, she believes, of her race, Debbie took private dance lessons instead. At 14, she was finally admitted to the troupe. "That was a lot of good time lost," she says now.

Allen then entered Howard University and graduated cum laude ("My daddy called it 'Thank ya Lawdy' he was so glad to see me out of school," she laughs). Allen drove up to New York in a friend's van. "I arrived on Broadway barefoot. All my shoes had been packed," she recalls. "It was an omen." Debbie, in fact, wound up with George Faison's modern dance company. The turning point of those early years, though, she says, was meeting Win Wilford, a CBS Records executive who works with artists like Earth, Wind & Fire, the Jackson Five and Teddy Pendergrass. They wed in 1975. "It's my first and only marriage," declares the determined Allen. "This is for life."

The Wilfords have a home in Westchester County and an apartment on the edge of Spanish Harlem which proved useful for West Side Story. To perfect her accent Debbie hung out in neighborhood bodegas. Nothing, however, could have prepared her for the scene in which she is almost raped by the Jets, the opposing street gang, at Doc's drugstore. "It's very degrading and very hard," she says softly. "After the scene, I come offstage and nobody talks to me."

As for the future, she's interested in choreography, movies (her first was The Fish that Saved Pittsburgh) and directing (she assisted on her own commercial for Dark 'N Lovely hair straightener) but hasn't written off dancing. "I don't know what I'll be doing when I'm 40," she reflects. "But Gwen Verdon and Chita are still kicking very high—and that's encouraging."