The floor became a trampoline as Julian Casablancas’ words came tumbling out of him like drunks spilling from a bar at last call.
He strangled his mic stand, his body taut, his vowels slack, as the ground beneath the pogoing crowd’s feet pulsed as if it were made of something elastic instead of concrete.
“He want it e-e-a-sy; he want it r-e-e-laxed,” The Strokes frontman sang at The Chelsea at The Cosmopolitan of Las Vegas on Wednesday. “Said I can do a lot of things, but I can’t do that.”
Casablancas was playing coy.
He and his band mates are defined by a kind of offhand intensity, of casual brio.
Is there such a thing as vigorous nonchalance?
The song in question, “The End Has No End,” affirmed as much.
It began with bassist Nikolai Fraiture, stoic as a wood carving, and drummer Fabrizio Moretti locking in with one another to form a rhythmic battering ram whose torque supplied the tune with its surging forward momentum.
Guitarists Nick Valensi and Albert Hammond Jr. added darting, nimbly played melodic accents that buoyed the thickset bottom end.
Casablancas mumbled and howled, howled and mumbled. Visually, they seemed to exert little effort.
Sonically, it sounded as if they were moving mountains, knocking them down like a kid kicking over anthills.
This is what The Strokes do: turn small gestures into huge anthems.
Their 17-song, 80-or-so-minute performance Wednesday came and went in a flash of invigorated languor.
At times, Casablancas embodied disaffection, singing hunched over, staring at his shoelaces during the funky shuffle of “Welcome to Japan” while sporting a sleeveless plaid flannel shirt and a hairdo that bordered on a mullet.
But then he would shoot his voice to rafters, like he did on “One Way Trigger,” which Hammond played from the back of his heels, staring at the ceiling, as if following the ascent of Casablancas’ soaring vocals.
Hammond and Valensi played circles around one another, their guitar lines occasionally coming together only to then sprint apart in different directions. It made a song like “Machu Picchu,” with its herky-jerky rhythms, feel like being a passenger in a fast-moving car that keeps changing directions suddenly, haphazardly, as if swerving to dodge potholes.
Following a triumphant “Hard to Explain,” Hammond held his guitar in the air, brandishing it like a broadsword after chopping down a foe.
Three tunes later, after a climactic, show-closing “Reptilia,” Valensi did the same. It was the only time of the night that they looked how they sounded.
The aplomb of songs like these and, even more so, “Heart in a Cage,” which literally made the room quake, was balanced by the spry, bright melodies of “Razorblade,” the prolonged sigh that was “Killing Lies” and the wistful “Under Control.”
“I don’t want to change the world,” Casablancas sang on the latter tune. “I just want to watch it go by.”
Again, this was him being coy.
He knows by now that he doesn’t have to choose between the two.
Contact reporter Jason Bracelin at email@example.com or 702-383-0476. Follow @JasonBracelin on Twitter.