There’s something unique about going to see a show at the First Unitarian Church. You walk downstairs to the sweaty, subterranean hall and push your way past a crowd of flannelled, snap-backed U Arts kids crammed right up to the stage. Headaches, the Toronto-based opener, saw the venue’s holy origins as an opportunity for a little humor, asking the crowd to bow its heads in prayer to “badass shit, rock and roll, and, above all else, pizza.”

The first two acts were, if not particularly memorable, successful in getting everyone stoked for Purity Ring. With suspense filling the room, there was palpable excitement as soon as the headliner appeared. The stage was decorated with big papier-mâché cocoons that, illuminated from the inside, transformed into a bizarre, alien egg-sac light show dominated by pastels and deep reds.

Musically, it can be difficult to pin down Purity Ring. The phrase “post-dub” comes to mind; they draw heavily on the robotic bass growls, and most of their songs are in that ambiguous tempo zone where song elements are questionably in half-time. However, Megan James’ pitched-down, saturated vocals push the meter towards something resembling synthpop. Anyone interested in indie, dubstep, hip-hop, or some combination thereof should give their first and only album, “Shrines,” a listen.

Purity Ring’s set confidently straddled the line between the sensual and the intellectual. James’ stage antics and Roddick’s dubby compositions gave the show a certain sexual energy, while the original light show and complexity of genre asserted its artistic seriousness. In the end, they put on a show that everyone enjoyed, from the stone-faced hipsters leaning against the wall to the kids with their glow sticks and rave kandi.