Donna McKechnie calls the solo show she’ll perform this weekend at the PlayGround Theatre My Musical Comedy Life. In so many ways, that title is perfect.

McKechnie is, after all, the dancer who dropped out of high school in Michigan at 16 to seek her professional fortunes in New York, got showcased work in her first Broadway show ( How To Succeed in Business Without Really Trying) at 18 and wound up as Newsweek’s cover girl on Jan. 6, 1975, twirling in a red leotard in the groundbreaking show that finally made her a star — A Chorus Line.

Yet during a long, revealing conversation over lunch at Joe Allen on Miami Beach, McKechnie also acknowledges that on today’s spectacle-driven Broadway, “musical comedy” is something of an old-fashioned term. And that her life in show business hasn’t exactly been one long collection of adventures with upbeat endings.

The mid-’70s triumph of A Chorus Line, for example, brought her fame and fulfillment, a best-actress Tony Award and a high-profile marriage to director-choreographer Michael Bennett, whose vision and interviews with McKechnie and other dancers brought A Chorus Line to life.

But those years also became, she says, “a litany of loss. Success and loss. Marriage and loss. Home and loss.”

The stories McKechnie tells in her 2006 autobiography Time Steps: My Musical Comedy Life are far more frank, nuanced and real than musical-comedy fodder. They involve a gypsy dancer’s sporadic homelessness, severe financial challenges, the inability to get hired for roles described as requiring “a Donna McKechnie type.” The triple-threat actress-singer-dancer has spent myriad hours in therapy over many years in order to live with truth. And at 68 (a vibrantly stunning 68, no less), she reflects on her personal and professional history — in the book, in her show and in conversation — with an unembroidered honesty.

Her 1976 marriage to Bennett, for instance, stunned many of their friends and acquaintances who knew that, although Bennett had dated women, he was a gay man. The two met as dancers on the television show Hullabaloo, and when Bennett choreographed Promises, Promises and Company, he gave her dances that highlighted her dazzling style. Then came A Chorus Line, that ode to Broadway’s usually anonymous chorus dancers and their sacrifices. And for McKechnie, life and art merged.

Of her year-long marriage to Bennett, who died of AIDS at 44 in 1987, she says, “We loved each other. We both suffered. We had fears about personal intimacy, and we used each other as a fortress.”

As the marriage was disintegrating, a back injury knocked McKechnie out of A Chorus Line. Then she suffered a potentially career-ending crisis as she was diagnosed with rheumatoid arthritis and told that, eventually, she wouldn’t be able to walk and might need 24-hour care.

“I could barely walk, but when the doctor said that, I just saw this big, ‘No!’ And then I thought, ‘What are you going to do about it?,’ ” McKechnie recalls.

Research led her to a 95-year-old physician, Sam Getland, who had begun to use diet, vitamins and supplements to treat patients who traditional medicine wasn’t helping. The eccentric doctor saw patients only from 10 p.m. to 5 a.m., in an old New Jersey Victorian home that McKechnie thought looked like “the House of the Seven Gables.” She took his advice, felt her pain recede as the months went by and eventually resumed her career — dancing again in A Chorus Line, taking the lead in a touring version of Sweet Charity (Bob Fosse’s final show), playing the key roles of Phyllis, Sally and Carlotta in different productions of Stephen Sondheim’s Follies.