Only a production of “The Rocky Horror Show” (now at Eastern Michigan University) would cause me, upon finding an orifice-themed obscenity carved into my car window’s winter-schmutz, to feel as though this act was an extension of the show, rather than something I should feel vaguely self-conscious about.

For on opening night, a handful of audience members had repeatedly shouted the same word that appeared on my car at actor Erik Hohnke, who plays sublimely naïve Brad.

When Brad and his equally sheltered fiancée, Janet (Esther Jentzen), suffer a car breakdown during a rainstorm, they seek refuge at the castle of an outré transvestite named Dr. Frank ‘N’ Furter (Matt Andersen), who seems to be hosting a bizarre, raunchy party while also giving life to a specially designed, Adonis-like man (Alex Justice).

Of course, thanks to the enormous popularity of the 1975 movie adaptation of Richard O’Brien’s campy stage show, a synopsis of “Rocky Horror” feels nearly obsolete. “Rocky Horror” has become a cultural touchstone, after all, spanning multiple generations of fans who come to screenings/performances in full costume and make-up, throw items referenced in the dialogue at the screen/stage, and contribute snarky, often profane lines of their own.

In this way, “Rocky Horror” may be the most genuinely interactive show there is. And indeed, some fans came in costume on EMU’s opening night and provided the performance with a running commentary. (Some of the show's funniest punchlines are those spoken by fans in the crowd.) But far more people purchased the $5 prop kit available for purchase in the lobby, so they could participate in throwing bits of rice at the stage, waving glow sticks in the air, and squirting water pistols.

The latter caused my notes, as well as Jentzen and Hohnke, to get pretty damp. But it’s pretty hard to resist a show that invites you to check all conventions and inhibitions at the door.

Director Phil Simmons fully embraces the show’s over-the-top sexuality and camp, inviting his performers to revel in the stylized seediness of this off-kilter underworld.

Yet what struck me as odd was that, even when Simmons’ entire ensemble was on-stage for a number, and despite the fact that I was sitting near the front of the auditorium, a sense of vocal cohesion and power seemed to be lacking. (And I didn’t get the sense that this was a result of Howard Cass’ orchestra overplaying, either.) Numbers featuring soloists thus fared better in terms of vocals, generally, than these ensemble numbers, though Stephanie Havenstein’s choreography was consistently cheeky and appealing throughout.

Andersen was opening night’s stand-out performer - in part, for mastering during a rehearsal period what I haven’t managed to do in nearly 40 years as a female: the taming of a fierce pair of six inch heels into submission. But Andersen also offered clear, confident vocals, crisply executed choreography, and - with help from Melanie Schuessler’s appropriately flashy and gauche (and well-fitted) costuming - projected the larger-than-life nature of his character with charismatic ease.

Early in the first opening night performance (there was an additional performance at 10 p.m.), though, the actors struggled to adapt to the crowd’s verbal contributions, and mic problems - both in terms of mics being turned off briefly, and a few students needing some more practice with them - plagued a few songs.

Jeremy Hopgood’s set design - which places the orchestra above the action, near the back of the stage - maximizes the space while also freeing up the pit for other, more creative uses; and John Charles’ lighting design is showy and bold, as most befits “Rocky Horror.”

Ultimately, though, you go to “Rocky Horror” to have some goofy, adult fun for a couple of hours, and Simmons, his creative team, and his cast provide that opportunity - as evidenced by several patrons wearing their prop kit party hats while venturing back into a cold winter night.

Jenn McKee is the entertainment digital journalist for AnnArbor.com. Reach her at jennmckee@annarbor.com or 734-623-2546, and follow her on Twitter @jennmckee.