From the point of view of the musician onstage, there can be no better sight than to look out mid-song and see a throng of people dancing.

On a good night, when the band is in synch and firing on all cylinders, the non-verbal communication between members locked into the same rhythms, anticipating one another’s next moves and simultaneously reacting to and spurring them on, is the most intimate exchange that people can have outside of sex.

When listeners are dancing in response to these sounds, this deep and visceral connection extends into the audience, the feedback loop expands, and the energy swap grows ever more intense.

You play harder, tighter, maybe a bit faster, and certainly with more spirit. You have to: The dancers depend on it. And it essentially is as close as you can get in modern days to one rock ’n’ roll ideal of recreating the bacchanalia of ancient times.

Vortis has been spoiled by several spontaneous and extended outbursts of dancing at recent gigs: There was a fair amount of moshing when we played with F*cked Up at the Empty Bottle, and the slamming was absolutely nuts during our late-summer road trip to Madison. When the fine fellows in Royal Pines asked us join them on a double bill Saturday at the Viaduct Theatre booked by Christa Meyer, formerly of the sublime Puerto Muerto and now in the process of putting together a new cello-driven group in between the duties of her day job, we wanted to do something special to mark our first time at this wonderfully friendly and eclectic venue tucked beneath the soon-to-be-dismantled bridge on Western near Belmont.

Hot & Heavy to the rescue.

Chicago’s hardest-rock burlesque troupe was formed about two years ago by the indomitable Danielle Call, a.k.a. Viva La Muerte, who may be small in stature, but who looms very large indeed as an undeniable life force. (She likes to describe herself as “a little hell-raiser.”) Starting with a handful of friends but now numbering 18 dancers who join her onstage at different gigs, Hot & Heavy grew out of Call’s two big loves: heavy metal and horror films. “And naked girls and metal just seem to go together!” she said.

This is not your grandmother’s burlesque troupe. In addition to the louder, nastier sounds that power it and a penchant for macabre twists and wicked humor in many of the routines, few of the girls fit anybody’s stereotype of a Playboy bunny. Their allure is in the sheer, unbridled, self-empowered joy that they display in unselfconsciously expressing themselves through dance, thoroughly losing themselves in the moment, and in the process taking off (strategic pieces of) clothing.

The Viaduct was the scene of Hot & Heavy’s biggest triumph to date—a full-scale burlesque rendition of the Pink Floyd epic “The Wall,” which they’ll reprise with 10 shows every weekend in January at the same venue—and when Call asked if Vortis would like them to join us for our Viaduct debut, we couldn’t say no. We’ve collaborated with the troupe a few times before, and the girls (and occasionally a guy) did their routines between sets. This time, we wanted to try something different, incorporating them into the set itself as a sort of bizarro-world/punk-rock take on the “Shindig” or “American Bandstand” dancers of yore.

This would be no easy feat, given the take-no-prisoners or pauses, banter-free, rapid-fire, express-train delivery that the band favors. Imagine trying to dance in time to a hurricane. But we sent Call and the girls a rough practice-space recording of our set—a typical 20 songs in 27 minutes—and she said they were up for the challenge. As indeed they were.

We came. We rocked. And so did Hot & Heavy, comprised on this night of Viva La Muerte, Red Hot Annie, Donna Touch, and Mai Atari, who mostly did their thing on the floor—pulling more than a few members of the crowd into the ensuing chaos and prompting others to spontaneously burlesque—while the band did its onstage, until we all came together for an encore of the immortal Naked Raygun’s “Rat Patrol.” (Hey, if we couldn’t be at Riot Fest, this definitely was the next best thing.)

One downside of being sequestered behind the drums behind a screen of cymbals is that I often miss all of the best stuff; I never heard about the guy who took a swing at our former lead singer mid-set or the night someone burned a flag in front of the stage until after the fact. On Saturday, all I could see beyond Tony and Louie Vortis and the vocal mikes was a blur of gyrating flesh and extended limbs, plus the occasional garment tossed onstage. But I could feel it, and it was sublime.

As for our partners in crime, the Royal Pines, Joe Patt and his band mates are at their best when their eschew their more traditional alt-country material—which is fine, but nothing we haven’t heard before—and wade through murkier, muddier, and much more Gothic waters. “You guys make me think of backwoods hillbilly goat-humping music,” I told them afterwards. I meant it as high praise—“We’ll take it as a compliment!” Patt said—but then it was that kind of night.

Viaduct photos by Mary Elisa Merrill.