A longtime, often-vaunted member of rap’s left-of-center underground, Tech N9ne has managed to forge a career out of being off the radar, of inspiring intense fan devotion (the Techn9cians even get their own affectionate name that sounds an awful lot cooler than Gleek or Juggalo), and of being gleefully, unapologetically off the wall. Those who can actually find a record store in their town may recognize Tech more from his album covers than his actual recorded output – his wild-eyed mug has graced the delightful covers of Sickology 101 and the Michael Jackson-aping Killer – but Tech aims to change all that with All 6’s & 7’s, a strange bid for mainstream acceptance that seems too clean for the underground and too weird for the pop charts.

Let’s get it out of the way: the radio-baiting on All 6’s & 7’s is blatant and obvious, yes, complete with slick production and guest spots from mainstream airwaves’ most pervasive presences (B.o.B shows up, Lil’ Wayne is here, T-Pain delivers a surprisingly heartfelt and untooled vocal another Autotuned-to-all-hell chorus-for-hire, Snoop sleepwalks through a verse in which he employs the exact same lazy flow he used on the Lonely Island record, Busta stops by, etc). It’s kind of a genius move for a veteran artist – after all, would Santana have resurfaced with such a vengeance if Dave Matthews, Rob Thomas, and Lauryn Hill, the pop music world’s most prevalent luminaries in 1999, hadn’t guested on his record? – and it could gain Tech N9ne some very real visibility.

And, let’s be honest – Tech deserves it. The guy’s a pretty terrific emcee, all told – listen to his flow on the fan-upping “Technicians” and the joyously funky “I Love Music,” or, perhaps more importantly, listen to his verse on the already-legendary “Worldwide Choppers”. Devised as a showpiece for a globe-trotting lineup of speed-rappers (from Denmark’s Ceza to Alabama’s Yelawolf), it’s a dizzying, 100mph triumph in which all involved are inspired to bring their best, and bring it hard. The foreign-language guys sure sound impressive, Twista’s verse is considerably more inspiring than the gimmicky (albeit impressive) bars he brings to his own tracks, and a show-stopping Busta Rhymes sounds revitalized, as wild and idiosyncratic as the Busta we all fell in love with years ago. It’s the crowbar that pries the “Arab Money” nail out of his coffin – but, perhaps most notably, Tech absolutely kills it on a long, winding, schizophrenic, delightfully spotlight-hogging verse. Speed may not be Tech’s primary gimmick, but he certainly proves able to hang on “Worldwide Choppers”.

And that’s paramount to this album’s success, ultimately: while Tech assembling a more mainstream crew than usual for a sprawling, 24-track record may reek of desperation to the slighted fan (a fact Tech addresses on this album’s “Love Me Tomorrow”), he’s never upstaged by his collaborators. Rather, he seems to have a genuine artistic synergy with a lot of them, as evidenced by the aforementioned “Worldwide Choppers,” or the terrific “Am I A Psycho?”, where Tech and guests Hopsin and B.o.B are all on the same wickedly wonderful wavelength, spitting schizophrenic phrases that’d make David Byrne and vintage Slim Shady proud in equal measure.

Of course, an album of this length is gonna lack a certain degree of consistency. Skits are largely short and harmless, but the album threatens to become an endurance test in its final fourth. Lil’ Wayne and T-Pain stop by to assist on the bawdy “F**k Food,” the first of a series of icky and uncomfortable sex tracks, but the track is largely saved by the comically dramatic production, and a par-for-the-course-wonky Tech verse. (Weezy is also predictably crazy, but he also predictably sucks; Wayne’s grosser sex rhymes often make tracks difficult to listen to, and hearing him weave a Tourette’s-worthy tale strung together by a certain feline-derived term is particularly off-putting. Do people still take Wayne seriously?) Two tracks later, the ante is upped with “Pornographic,” which features E-40 (delightful, as always) and Snoop Dogg (sleepwalking, apparently), but more importantly, also features a chorus that rhymes “make a porno” with “eat you up like DiGiornio”, as if to ensure that people who own the album will NEVER listen to the track on purpose. (Except for women, because I’m not sure that there’s anything quite as sexy as comparing a lover’s lady-parts to a $6 frozen pizza.) At least “Overtime” – the least-gross sex track on the record, to damn with faint praise – only commits the sin of boredom. (The less said about the literally-unlistenable “You Owe Like Pookie,” the better.)

Still, with the exception of that dubious section of record, Tech often brings it with All 6’s & 7’s, a calculated bid for mainstream acceptance that manages to, to paraphrase the man himself, make the mainstream go Tech. It could’ve simply been the other way around, and props to Tech for striking a compelling balance. At 24 tracks, it may not be all gold, but there are things here good enough to remain mixtape staples for years to come.

Grade: B+