At the outset of Anti-Pop Consortium’s second album, Arrhythmia (Warp), you’re already dead. Bells toll and peal in loosely organized cacophony; drone tones beam in from outer space and cut an unforgiving path through your complacency. Call it futurist melancholy. It’s your end. But it’s also the wake-up call. This is the new avant rap, even if everyone’s been toying with cadence and molding flow like clay since the early ’90s. And even among innovators, Anti-Pop Consortium have always stood out . . . sorely.

Anti-Pop Consortium — the trio of Beans, Priest, and M. Sayyid — spend little time preoccupied with the dalliances of those in the mainstream. Like Arrhythmia’s first track, most of the group’s debut album, The Tragic Epilogue (75 Ark), played like a hip-hop death dirge. But here, they switch attitude; every other song on Arrhythmia brings redemption. While mainstream artists focus on the value of catchy hooks, Anti-Pop find themselves fascinated with intriguing, left-of-center sounds, courtesy of their in-house producer, the ever-impressive Earl Blaize. There are hollow, finger-tapped drums on "Bubbles," ping-pong-paddle smacks on "Ping Pong (The Return)," horror-video-game beats on "Mega," and quick, sharp glitches that act like bugs picking at your skin in "Dead in Motion."

Fortunately, Anti-Pop have the flows to match. Beans is the champion of non sequitur free-form verse: his tongue tricks buzz and dip in unpredictable ways. Sayyid has the most conventional rhyme style — which is to say that gravity at least has a marginal effect on his words. In "Ping Pong" he expounds on his "symphonic monopoly philosophy" and promises to "wreck your rep like Eddie [Murphy] on a LA strip with RuPaul." Even his braggadocio is a bit irregular. On "Dead in Motion," he boasts, "What I’m saying is this/Sayyid’s on top of the shit/Like I’m walking around with a toilet strapped to the hip."

But even in a battle of giants, only one can stand tallest, and Arrhythmia is very much Priest’s album. "I can write a rhyme where nothing rhymes," he brags, his baritone impossibly hollow, implying a wide-open vortex of thought. On "Conspiracy of Truth," a sort of post–September 11 track, he pleads, "These words are all I have to offer/The author lost in his thoughts/A walking New Yorker covered in ash/Behind the crash/With an open gash . . . Are you sure what you’re fighting for/War with a cinematic score?"

Anti-Pop don’t just eschew the mainstream — they’re also not too sure about the progressive-minded underground. Priest battles both on "Ping Pong": "Craft a masterpiece with a glass of Shasta after I slash a rapper with a protractor/Flow factor blow back the cap of a backpacker."

Of course, backpacker superiority is almost as potent in London as in Anti-Pop’s New York. Over there, where the scene is even less beholden to hip-hop tradition, outer sounds are par for the course, and New Flesh lead the way on their new Understanding (Big Dada/Ninja Tune). Like Anti-Pop Consortium, New Flesh bring lyrics — twisted dancehall chanter Toastie Taylor shines in particular on "Read Child Soldier," a brooding tale of youth gone wild that ends with Toastie’s protagonist murdering his father figure out of disillusionment. And they’ve got fantastic taste in guests, importing Anti-Pop’s Beans, Blackalicious’s breath-holding trickster Gift of Gab, the notorious hip-hop alien Ramm:Ell:Zee (legendary for his no-wave era collaboration with K-Rob, "Beat Bop"), and Brit up-and-comer Robotic E.B.U.

But as with Anti-Pop, the sound’s the thing. They call it "bouncement," which Big Dada label owner Will Ashon describes as being at the intersection of the bounce and the basement, reggae-style. Indeed, for British hip-hop — a notoriously dry genre — Understanding is downright sassy, shimmering with rude-bwoy disco, skittish snares, unexpected diva wailing, and, as they describe it on "Stick & Move," "dancehall Afro-funk." "More Fire," which borrows its name if not its politics from Capleton, pairs Southern stutter paranoia with madly intersecting whistles and bleeps to convey a sense of impending doom. "Communicate," a sexy disco track yanked and stretched and kick-snared into true funk, gives way to the screwed-down dub of "Bound," which in turn morphs into postmodern glam funk on "Transition."

But the album’s musical tour de force is "Real Child Soldier," a track dripping with depressive jazz-trumpet lamentations. It’s the perfect backdrop for Toastie’s tears. And there you are . . . dead again . . . naturally.