The Pulitzer Prize and Tony Award-winning 1975 musical “A Chorus Line” describes the struggles of dancers auditioning for supporting parts in a Broadway ensemble, yet its success depends upon leading role-quality performances. San Francisco Playhouse’s production of the classic show, onstage through September, is full of them.

The cast members, great singers and actors as well as dancers, truly deliver, offering modern audiences the thrilling and touching experience that illustrates why the show (music by Marvin Hamlisch, lyrics by Edward Kleban; book by James Kirkwood ad Nicholas Dante) was such a phenomenon nearly 50 years ago and why it still resonates today.

Directed by SF Playhouse co-founder and artistic director Bill English, in a group and one by one, the players bring to life the strengths and vulnerabilities of the auditioners.

Dancers reflect on their lives as performers at the audition in “A Chorus Line.” (Courtesy Jessica Palopoli/San Francisco Playhouse)

Tony Conaty is sweet and sprightly as Mike, whose tapping journey started when he was a kid watching his sister’s dance class, while Alison Ewing as the jaded Sheila, Jillian A. Smith as the insecure Bebe and Danielle Cheiken as the lonely Maggie nail the soaring vocals in the emotional “At the Ballet.” On the other hand, M. Javi Harnly and Gwen Tessman bring on the comedy as the couple describing the challenge to singing on key. Melissa WolfKlain as Val also gets laughs regaling the benefits of cosmetic surgery. Alex Rodriguez as Paul does well with a dramatic coming out story, while Samantha Rose Cárdenas as Diana affectively shares her feelings about her unsympathetic drama teacher in school.   

Likewise, Keith Pinto is appropriately tough as Zach, the show’s director whose unorthodox method provides the compelling plot backbone of “A Chorus Line,” as he puts the typically behind-the-scenes performers in the spotlight when he demands that they offer personal details about their lives as their audition.

His back story also comes to light in his interaction with Cassie, his ex, whose career took her beyond the chorus; he’s not kind to her as she tries out for a small part in the upcoming show. Nicole Helfer’s performance as Cassie, who has the big solo dance in “The Music and the Mirror,” is no surprise; she’s also this production’s choreographer, who based her dance on the iconic work of Michael Bennett, “A Chorus Line’s” creator and original choreographer and director.

Cassie (Nicole Helfer) shares her struggles with her ex, director Zach (Keith Pinto) in San Francisco Playhouse’s “A Chorus Line.” (Courtesy Jessica Palopoli/San Francisco Playhouse)

And other hopefuls on the line who don’t get their own extended featured moments — Dalton Bertolone as Greg, Chachi Delgado as Richie, Zach Padlo as Don, Maggie Connard as Judy, Ruri Kodama as Connie, Zeke Edmonds as Mark and Nicholas Yenson as Bobby — and Ann Warque as Zach’s assistant, round out the uniformly impeccable cast.

Zeke Edmonds, center, as Mark describes his childhood, to the amusement of fellow dancers Val (Melissa WolfKlain) and Diana Morales (Samantha Rose Cárdenas) in “A Chorus Line.” (Courtesy Jessica Palopoli/San Francisco Playhouse)

Musical director Dave Dobrusky leads the band in Hamlisch’s unforgettable score. After one early performance in SF Playhouse’s nice long run, patrons leaving the theater were happily humming the famous tunes on their way out.

It’s a testament to “A Chorus Line’s” power that the announcement of the dancers who actually get cast in the show is eclipsed by the universal feelings captured in the songs — all the way from “One” to “What I Did for Love.”  

“A Chorus Line” has been extended through Sept. 16 at San Francisco Playhouse, 450 Post St., San Francisco. Tickets are $15-$100 at sfplayhouse.org or (415) 677-9596.