Those who stopped by Webster Hall on Friday night to sway along with the harmonic folk rock of Heartless Bastards may have wondered why the floor was pulsing beneath them. Who was that screaming bloody murder? Was he OK? And why was everyone just cheering his evidently painful demise?
 
Earlier Friday evening the Studio At Webster Hall hosted a night of metal appreciation headlined by Massachusetts post-rock royalty Caspian. But the noise—and the screaming—started long before Caspian took the fog-drenched basement stage.
 
Tidal Arms, a Brooklyn power trio that tags its sound as “stormy psych-rock,” opened the show at 8 p.m. Tidal Arms seems a band still finding its sound. Though the players turned in 35 minutes of solid rock, mostly heavy instrumentals with occasional screaming vocals, their tendency to cram too many competing (though tasty) riffs into each song complicated audience efforts to sustain a head-bopping groove beyond 15- and 30-second bursts. Floppy-haired frontman Tom Tierney briefly traded shout-outs with his girlfriend, who was adrift somewhere in the growing crowd but otherwise instigated minimal audience interaction, save a brief introduction to the new single “Wooly Pictures .” The track was released a few days before the show, but Tierney admitted to some applause that it was the first song Tidal Arms recorded together as a band. Expect more jams to come as the group further defines its sound.
 
Pianos Become The Teeth took the stage next. The band is a Baltimore, MD, rock quintet comprised of two guitarists, a bassist, a drummer and one lanky vocalist named Kyle Durfey, whose interests include galloping about the stage in skinny jeans, primal screaming and clawing at his sweat-drenched cotton T-shirt like a suspicious primate wearing clothing for the first time. Their initial request for “WAY less fog, please,” was an early indicator of where their aesthetic diverges from Caspian’s. Durfey’s exhausting Andrew W.K. antics and feral Damian Abraham howl placed Pianos’ style much nearer Tidal Arms’ punk sensibility than Caspian’s ambient metal, but it nonetheless served as hyper-capable pump-up music.
 
Caspian guitarist/synth man Philip Jamieson easily stands over six feet tall and had to crouch under the low Studio ceiling as he bussed gear from back- to center-stage. He and three other guitarists, a bassist and drummer speechlessly crowded the Studio’s low bandstand in a shroud of fog and blue/orange backlighting before exploding into an hour-long set that melted as many faces as it did expectations based on the band’s recent live LP, Live At Old South Church. Where its live album offered a clean, metered selection of rising and falling action, Caspian’s show at the Studio was pure climax.
 
Even Caspian’s few slow-starting songs, like “Moksha,” were shredders in disguise. From the first instrumental barrage, all five band members not seated behind a drum kit leapt and thrashed in wild orbit with their pulsing metal tones. Imperfect sound mixing created a sustained echo of fuzz throughout the entire set, making it difficult to hear the nuances of each guitarist’s contribution above the din of double kicks and crashing cymbals, but it didn’t matter. Caspian traffics in texture, and the swell of sound waves caroming around the Studio’s intimate walls were textured enough to taste. Midway through the set Caspian teased an untitled new song, which began with two drummers playing a broken Sleigh Bells-style beat before the band’s signature arpeggiating layers inevitably took over. Even this unfamiliar track kept audience members in groove.
 
While most present in the packed basement room sustained themselves with head-bobbing or swaying side to side, select pockets of hardcore and hard-drinking fans were out to prove their love of Caspian. A league of them in matching black hoodies huddled throughout the show in a sort of makeshift Roman tortoise, their arms linked around each others shoulders, hopping up and down to the swelling music in a cathartic bro-out. Two inebriated kids in the front row made out so fiercely during one tide of high notes that they literally lost their footing and tumbled to the dirty Studio floor. Their comrades quickly helped them back to their feet.
 
Show closer “Sycamore,” which also closes Live At Old South Church and may be the only way Caspian knows how to bring its set to a pummeling conclusion, began with four minutes of woozy ambiance before erupting into an aux percussion flash mob. Event staff deployed extra snares around drummer Joe Vickers’ kit, so as the song reached its peak all four guitarists swapped their instruments for sticks to rattle out a triumphant, unified march that closed the show. Only bassist Chris Friedrich was left holding his instrument as the four errant musicians hopped and head-banged the set to a powerful finish around 11 p.m. There was no encore. There didn’t need to be.