To call Busdriver [click to read] is an acquired taste would be an understatement. His raps thrash fiercely, pushing the double time chopped flow of his Project Blowed [click to read] mentors (Freestyle Fellowship, etc.) into its avant garde extreme. He’s  basically the closest rapping has ever actually come to Free Jazz and, like the skronkiest of out Jazzmen, Bus is almost completely unlistenable to the neophyte. Think of a wordier Frank Zappa channeling both Twista [click to read] and Ascension-era John Coltrane. But despite this willing inaccessibility he’s also a vicious technical rapper, to the point of showboating.

Jhelli Beam, his sixth proper solo album is simply unbridled ‘Driver. The production, courtesy of longtime collaborators like Daedalus, Omid and Nobody is appropriately dynamic, sputtering and splitting in tiny electronic bursts, sporadically changing directions but never jumping too far off the ledge. On last year’s Roadkill Overcoat, Bus was delving into more adventurous territory, trying his hand at fuller-formed songwriting and ill advised Indie Rock inspired experiments. There’s very little of that here. It’s a rapping album. He raps a lot, and quickly.

Which is partially why Jhelli Beam succeeds and partially why it fails. The album works just fine as a sheer display of virtuosity but its message is nearly indigestible. Which is a shame because it really seems like Busdriver has something pressing to say, seemingly about racial and identity politics on the indie Rap circuit. And as bespectacled, corduroy clad black man who often performs to largely white and/or nerdy audiences, it’s a safe to assume that he’d have a unique perspective on the topic. But he’s too distracted by an inexplicable desire to rhyme “Martian’s sphinx” with “Barton Fink” or “Large intestine” and “Charlton Heston” to actually deliver his message.

“Least Favorite Rapper,” a relatively subdued duet with fellow Project Blowed refugee Nocando is the closest Bus comes to actually articulating any sort of agenda. He assumes the role of “your least favorite Flavor Flav impersonator” for a three and a half minute blur of Idi Amin references and sarcastic self-deprecation in the name of violently deconstructing every other rap archetype from the sneaker geek hipsters to the dope boy. If Busdriver does have a modus operandi it’s strictly tongue in cheek. And hilarious.

But Jhelli Beam too often feels like a regression, like he’s rapped himself into a corner. The Omid-produced “Me-Time (With The Pulmonary Palimpsest)” is a pretty shallow rehash the rapping-fast-over-classical-music precedent set by 2001’s “Imaginary Places.” That Tony Hawk-approved cult classic flipped Bach; “Me-Time” grabs a chunk of Mozart. Same difference. Unconcerned with innovation, Busdriver is running in circles and flailing. But maybe flailing is what he does best.