As though it weren’t enough of a sign that one of the characters arrives for a Broadway dance audition wearing a hideous pair of plaid pants, the landmark 1975 musical “A Chorus Line” (originally conceived by Michael Bennett) already feels like a relic from some bygone era, at least in certain respects.

When a dancer in the story sustains a serious injury, nobody whips out an iPhone and dials 911; instead, someone darts offstage to phone a doctor about making a "house call." And what may have been a startling revelation 36 years ago – that a lot of "chorus boys" might be gay – seems clichéd by now and overemphasized on top of that, with three different characters delivering monologues on the subject.

From a production standpoint, however, “A Chorus Line” remains a daunting assignment, which likely explains why it’s rather rarely done. (I can’t recall another local production of it in the last 20 years.) Whatever the end results, one thing to be said for the folks at Aurora Theatre is that they’ve never been known to deny the courage of their convictions.

Chief among the show’s challenges is that it requires no less than 18 strong dancers. If they can sing and act as well, so much the better, but unfortunately this isn’t always the case in director Anne Towns’ Aurora ensemble. Make no mistake. The dancing, choreographed by Jen MacQueen, is largely impressive. It’s the singing and acting that routinely stumbles.

The script by James Kirkwood and Nicholas Dante follows the process of elimination during a “cattle call” audition, where a director named Zach (appropriately played by Aurora artistic producer Anthony Rodriguez) is casting the chorus for an upcoming musical. Wanting to learn what kind of people they are – not just what kind of dancers – he gives each of them moments to tell their own stories.

But too many of the characters are interchangeable or extraneous and too many of the performances lack distinction and definition. Unlike with the well-drawn contestants from “The 25th Annual Putnam County Spelling Bee,” say, we don’t have as much of a vested interest here in which ones make the cut or which ones don’t.

Acting honors go to David Rossetti (as Paul, the least flamboyant of the gays) and Meredith Campbell (as the cynical Sheila). It would have been nice to see more of Leslie Bellair (as the diminutive Connie) and Greg Kamp (as the innocent Mark), both of whose scenes are shortchanged by a recurring “montage” number.

Among the memorable songs (music by Marvin Hamlisch, lyrics by Edward Kleban), highlights include Marissa Druzbanski’s solo “What I Did for Love” and the Nick Morrett-Angela Harris duet “Sing.”

In the dancing department, Pamela Gold (as Cassie, a fallen diva and Zach’s former flame) is most convincing. For all their right moves and even from a back corner of the balcony, some of the others look a bit old – and more than a few of them out of shape, frankly – to be truly believed as Broadway hoofers.

To borrow the title of another tune in the show, “Dance: 10; Looks: 3,” indeed.

Theater review

“A Chorus Line”

Grade: B-

Through Sept. 4. 8 p.m. Wednesdays-Saturdays; 2:30 p.m. Saturdays-Sundays; 10 a.m. Wednesday (Aug. 31). $16-$35. Aurora Theatre, 128 Pike St., Lawrenceville. 678-226-6222. auroratheatre.com

Bottom line: Not quite a singular sensation.