PHILADELPHIA -- The Center City hotel room is the pits and the dressing room is miles away and there were rows of unfriendly, unsold seats in the old Forrest Theater on this weeknight, but Donna McKechnie -- dimpled, diminutive 1976 Tony Award-winning dancer and star of "A Chorus Line," who did a disappearing act for almost a decade -- is glad to be here.

She has kicked and warbled and sweated her way through two hours of Bob Fosse's "Sweet Charity" (opening tomorrow night at Washington's National Theatre), and at the age of 44, after two failed marriages (the first to a compulsive gambler, the second to "Chorus Line" director Michael Bennett, who died of AIDS this summer), hits, flops, raves, pans, bouts with rheumatoid arthritis and crippling anxiety, her comeback is a personal as well as professional triumph.

"I'm so grateful to be doing this," she will say later. "I feel like I've earned this."

She stands in the dressing room, bathed in the hot white light of the makeup mirror, cards and notes of congratulations stuck in the beveled edges like flags, a box of Beuti-Lashes on the counter next to tiny pots of crayon-colored creams and iridescent grease. It smells sweet and warm and achingly familiar, the way old schoolrooms smell of apples and slightly sour milk. Tiny beads of perspiration glisten on her upper lip as she smoothes her leather miniskirt and smiles broadly, batting the two-inch false eyelashes, which are something of a trademark now.

"Darling, how good to see you!" An older woman in a silver bouffant and sterling cuff bracelet and Elsa Perretti squiggle-pin throws her arms around McKechnie. Earlier, the woman -- clearly unaccustomed to putting small bits of change into anything -- had wrestled with a pay phone to call a friend back in Manhattan. "I've come over to see Donna's show. It's so crisp. Bob {Fosse} has been here and Gwen {Verdon}. Uh-uh."

The other dancers, half her age, climb up and down the stairs outside McKechnie's door, their exotic painted faces and slicked-back hair covered by white nets blurring any gender lines.

Back in the alley, the warmth and yellow glow from the stage door bathe the cobblestone street in an eerie spotlight as the young dancers chat with friends, leaning on one foot and then the other like ponies, their nylon bags slung over their shoulders hobo-style. They don't move on, but stay, wanting to hold the night's performance for a while longer, the magic and the laughter and applause still fresh.

Dear God, I need this job.

"With this part, I do feel it was written for me. But it took me months to get to that abandoned place. To make it my own. Every actress who does this part, I'm sure, says that." Debbie Allen and Ann Reinking did the Broadway version of this production. McKechnie is now taking it on the road -- Washington, Boston, Los Angeles. She is crossing the intersection at 16th and Spruce, on her way to lunch. She wears a short satiny dress with a long slit up the side, revealing disciplined legs in black tights. Her feet, slightly misshapen and endearingly knobby, are crammed into low heels.

She wears heavy makeup -- carefully outlined and filled-in crimson lips, tawny blusher, the daddy-longlegs lashes. She is surrounded by an invisible floral garden. "I called it 'Frack-ass' for a long time," she says, identifying the perfume. "But then my dresser said, 'No, it's Frac-ah.' " The last syllable is accented with faux French dramatic flourish.

Her normally brown hair is dyed the color of Hawaiian Punch. She is perky, with her upturned nose and lilting voice, and nice to strangers. The way theater people, and few film people, usually are.

The part of Charity Hope Valentine, the emotional doormat who seems to be in vogue ("Women Who Love Too Much" comes to mind) does seem tailor-made for McKechnie. Although she never got tattooed for love, McKechnie still bears the scars. Yes, she says, her life experiences have helped her assume the role. "I could have done it five years ago," she says, "but I'm glad I waited. I wouldn't have been as good as I am now."

Fosse agrees. The choreographer-director says he cast McKechnie after seeing her return performance in "A Chorus Line" last year. "I think she was better than the first time. Her acting was so much better." He adds, "I adore her ... I've seen 12 of them {actresses} do it," referring to the role of Charity -- including his first wife, Verdon. "I'd say she's one of the best."

McKechnie takes a seat outside in the garden of the restaurant, orders a mineral water, a black coffee and an Alaskan king crab salad. "My nutritionist told me to stay away from any Atlantic Coast seafood. The toxins."

The oldest of three children, she was born and raised in Pontiac, Mich., in a lower-middle-class family of Scottish origin. Her father was a tool-and-die manufacturer. "He really struggled. My mother wasn't a stage mother, but she loved art. She loved Jeanette MacDonald."

McKechnie says she was probably 3 years old when she began dancing in the living room with an imaginary Indian chief. At the age of 7 she went to dancing school. It was an escape, she says, from her conservative family. "When I heard that beautiful music, having none of that in my home, it was like a world opened up. It totally changed me. Movement in dance was never that important to me. It was always the music."

At 15 she ran away from home, headed for New York. Her father came and brought her back. She ran away again. Her parents took her to a judge. "I think they were trying to scare me," she says. Finally, they let her go. "I felt this destiny. I don't know where the voice came from. I was always the perfect child -- which is why it was shocking that I ran away. I had planned my escape from the time I was 7."

She told Newsweek, in a 1975 cover story: "I always felt a need for my father. That's really why I used to dance around that living room."

The puritanism of her family, she says, "was worse than the Bible Belt. If you got too excited about anything, it was threatening. It looked like you were having too much fun. Pleasure was a sin. I was raised that way. So you start feeling like a sinner at 7."

Music and dance, she says now, "made me feel that I had a connection with loving feelings. It could feed me. I was into a lot of fantasy."

McKechnie's first job in New York was in the corps de ballet at Radio City Music Hall. She then won a place in a touring company of "West Side Story" and, at the age of 17, made the chorus of "How to Succeed in Business Without Really Trying."

"Being a little ballerina," she says now, "I thought it was a very condescending thing to audition for Broadway."

But McKechnie, formerly with the Detroit City Ballet, had already been turned down by American Ballet Theatre, and took the rejection hard. She abandoned ballet -- not only performing it but also attending it.

In "How to Succeed" she worked with the legendary Frank Loesser, who scored the show. "It was really like going to college. He coached me as an understudy. He was like a Damon Runyon character." She holds up an imaginary cigar. " 'Honey, make the gesture first. Then sing the note.' I don't know why, but it works."

She worked steadily, and hard. "One of the things that made me a very good dancer, aside from the potential I had, is that I had this perfectionist thing which got me into trouble. When you're told that nothing's good enough, that you're not good enough ... I worked to excel."

She spent all her money on acting and singing and dancing lessons. Her first acting partner was Jon Voight. She also took classes with Mia Farrow and Michael J. Pollard. Gwen Verdon was her first dance captain. Does it bother her that her name is not widely known outside the theater world? "You don't go into theater for fame or to make money," she says. "If it happens, it's wonderful."

While her professional life was soaring, McKechnie's private life was not. "The willfulness and determination that got me where I was, that I needed to survive, got in my way along the way and stopped me from sitting back and taking notice."

She was married at the age of 20. "Here's the 'Charity' part of the tale," she says, laughing. "He was a very charming, charismatic man who had a sick gambling problem." McKechnie would save him. One day she arrived home in time to see U.S. marshals hauling away their belongings. McKechnie walked into the bedroom to find her husband on the phone -- placing bets. "I said, 'What's that man doing in our living room?' He said, 'Don't bother me, can'tcha see I'm on the phone?' "

She divorced him, but not before her father had mortgaged the family home to pay off her husband's gambling debts.

She had now graduated from the chorus line to soloist. Friend and mentor Michael Bennett (whom she had met in the mid-'60s while appearing on the television dance show "Hullabaloo") featured her prominently in two of his shows, "Promises, Promises" and "Company." There was a long relationship with actor Ken Howard. She went to Hollywood. It was a bust. She considered quitting show business.

Then, in 1975, came "A Chorus Line." Bennett had asked old theater friends to tell their stories. From the hours of taped conversations, the show was born. Although the character of Maggie was her story, McKechnie played Cassie, the director's ex-girlfriend who bombs in Hollywood and begs Zach to put her back in the chorus line. She won the Tony for Best Actress, and then, in 1977, quit the show and married Bennett. They were divorced soon after.

"I had this idea if I got married, I would have a wonderful life. And I wouldn't need show business. I really wanted a family. I realized I was running to this fortress of a thing called 'Happy Marriage.' I didn't understand you could have both. I had all these concepts that were very bad."

She and Bennett, she said, were both being inundated with offers. In that first flush of celebrityhood, they clung to each other. She prodded him into buying a Rolls-Royce. The marriage's demise, she says now, had nothing to do with Bennett's homosexuality. (She says, in fact, that the choreographer had abandoned his gay persona with the help of a psychiatrist.) When he died of AIDS in July, she says, she hadn't known he had the disease. "My consolation is that we remained friends. Professionally, it was wonderful to have reunions with him over the years."

Last year she returned to "A Chorus Line" to play Cassie for eight months. "The best part of us still existed, and that's my only consolation. Two people who grew up and say, 'We made a mistake but we still care.' I can't talk about a lot of it. I'm still very upset. I can't be objective about it. I'm very proud of him. Even talking about any mishap in my life with Michael, it's something even now I treasure because he's really the most influential person in my life, outside of my parents."

Yes, she says, she has been tested for AIDS. "I think everyone should do it. It's such a frightening thing for people. I would do anything to dispel the idea that it's just a certain elite group that you have to worry about, or the arts. It's a civilization problem."

She has told her friends to take the test. "That's why it's so important to do it," she says. "You have to run right to your fear of anything."

After the divorce, "I went through a whole year of not really sleeping," McKechnie says. Then one morning she woke up with a terrible stiffness in her joints. Her fingers started to swell. The diagnosis: rheumatoid arthritis. Doctors told her she would never dance again. She took 18 Bufferin a day and was engulfed by depression. "I would be walking down the street and, not even knowing what my thoughts were, I would burst into tears. I was so afraid to go out. I called it 'The Year of the Bedroom.' 'Mister Rogers' was the only television show I could watch because he talked softly."

People began to wonder what had happened to McKechnie. One minute, she was on the cover of Newsweek. The next, she was gone. "I didn't want it known," she says of the arthritis. "I kept it pretty much a secret." Finally she found a nutritionist in New Jersey who put her on a special diet and taught her relaxation techniques. She moved to Los Angeles and got into analysis, one hour a day for three years, and realized that her physical problems may have been rooted in psychological ones. "There was an identity problem. Working so hard all those years, your identity becomes your ambition. I was only as good as my reviews were."

She returned to work, slowly, taking parts in regional theaters and guest shots on television shows. "Things I could do without dancing." She agreed to return to "A Chorus Line" against the advice of friends. Fosse saw her and offered her the road tour of "Charity."

"The choreography is very different for me. All your energy goes in. Nothing explodes. Everything is contained. Nothing goes beyond your fingers. In 'Chorus Line,' I threw myself from wall to wall. My barometer during the show would be that my lungs would be burning. I have none of those sensations here." She laughs. "Though I sweat a lot."

Dancers, she says, are by nature shy. "When you see dancers on the stage, especially in Fosse things, it's 'look and don't touch.' That's the message. Everything has to look pretty. It can't be real."

The fantasy continues: Daddy will take her in his arms and twirl around that living room. "I'm going to be criticized for saying this, but most people who go into show business are neurotic. You make the audience your parents. You're drawn to the business. If you can stay in it long enough, if you can see the other side of it, you can work through it."

McKechnie obviously has. The day she decided she could face life alone she met Andre, a tall and handsome member of the Royal Canadian Mounties. They are planning a life together. Although it's too late for children, she says she would be willing to adopt. "Like Charity, I always say, 'Things are looking up for me.' This time I didn't give my money away. This time I didn't get tattooed. I'm happy with the way things have turned out. I would encourage anyone to make the most of their mistakes. What else can you do?"

Will the hapless Charity ever change her ways?

"Oh sure," says McKechnie, eyes widening. "She'll go into therapy."