Bradford Cox, lead vocalist and frontman of Deerhunter, America’s most consistent alternative rock band, is volatile and unpredictable. Two Februaries ago, he played at the Binghamton Undergrounds, where he seated the crowd and transformed the night into a question-and-answer session. Just weeks after visiting campus, he played “My Sharona” for a full 60 minutes at the Cedar Culture Center in Minneapolis, taking the sarcastic suggestion of an audience heckler in the name of the “birth of punk and the death of folk.”

Last month, Deerhunter played the eponymous track from “Monomania,” their newest 4AD LP, on “Late Night With Jimmy Fallon.” Dressed in a frazzled black wig and adorned with lipstick and bloodied fingers, Cox nonchalantly walked offstage and ended his band’s return to television as abruptly as it began.

So, for a band whose white-knuckled grip on contemporary rock is prolifically organized and well-respected, how does Deerhunter defend itself against its ingenious, troubled leader?

The raw energy that poured from every second of the band’s Fallon performance answers to this uncertainty. Behind Cox’s heady themes and uncompromising aesthetic is a troupe of modestly professional musicians. They add new life to Deerhunter’s catalogue with this year’s new album, which is both optimistic and jarring.

While the band’s 2010 breakout “Halcyon Digest” brought gorgeous clarity through a commanding blend of ’90s shoegaze, millennial pop and old classic rock, “Monomania” retreats into unfettered noise. Instead of shimmering beauties like “Helicopter,” “Desire Lines” and “Agoraphobia,” Cox’s new “nocturnal garage” sound is fleshed out here, yielding scrappy rough diamonds like opener “Neon Junkyard” and The Strokes ode “Back To The Middle.” The band’s choice to record the album directly to eight-track recorders gives it a corroded sheen that harks back to its earliest release “Turn It Up, Faggot.” Additionally, the departure of longtime bassist Josh Fauver led to the band’s expansion, adding both a new bassist and a rhythm guitarist.

These factors have all but transformed the band’s energetic brand of contemporary rock. Cox’s introspective narratives are still rampant, consuming middle cuts “Dream Captain” and “Blue Agent” entirely with accounts of eager excitement and bitter jealousy. Guitarist Lockett Pundt’s uncanny ear for rock’s catchier side is ever stronger, generating “The Missing,” one of Deerhunter’s finest pop songs to date. Drummer Moses Archuleta’s percussion is neither too diffuse nor too aggressive and heightens tensions in just about every track.

It’s the blatantly aggressive sequencing of the album that makes it an innovative and new release for Deerhunter. From “Cryptograms” onward, even including Atlas Sound and Lotus Plaza, Cox’s and Pundt’s side projects, relied on an impeccable flow and a cohesive, overarching theme. Much of the appeal of “Cryptograms” and “Microcastle” came from their psychedelic, sedated haze, complete with flowing interludes and nonstop sound from start to finish. “Monomania” confronts that meticulous linearity and douses its listeners in cold water after every song.

The howling dreams of “Neon Junkyard” abruptly yield to the unforgiving garage sensibilities of “Leather Jacket II.” Pundt’s pristine pop offering “The Missing” feels snubbed through its transition into the obvious country road song “Pensacola” — Cox almost sounds like he’s smirking when he sings, “Well I’ve been waiting so long to say bye-bye.” This anti-flow constitutes the entire album, which ends perplexingly with “Punk (La Vie Antérieure),” a final track that feels like a lost Atlas Sound B-side.

After the brilliantly curated mélange of just about every rock aesthetic on “Halcyon Digest,” “Monomania” feels like a necessary dirtying and a positive exercise in expelling Cox’s personal anxieties and fears after his quasi-meltdown last year.

For new fans, “Monomania” is a monolith of noise and American rock romanticism. For longtime devotees, “Monomania” might not stand up to the sprawling reverb that the group constructed over the span of its past four albums, but it deserves a place at the Deerhunter table.