Still at school when he signed his 2008 Columbia Records deal, British hip-hop hope Chipmunk attempts to prove he's all grown up for his sophomore album, Transition, which eschews the playful urban-electro and grime-pop of his debut, I Am Chipmunk, in favor of a harder-edged R&B sound designed to showcase his slick MC skills and bold, self-aggrandizing lyrical approach. It's a clever move considering the annoying ubiquity of his previous dance-oriented material, but it's also one which appears to focus on a potential transatlantic crossover, thanks to an impressive guest list featuring some of the U.S. urban scene's hottest properties. Out of the eight star-studded collaborators, only one originates from his own shores, fellow London rapper Wretch 32, who adds his languid, laid-back delivery to the sparse beats and video game-style production of "Armageddon." But despite its lack of homegrown talent and production by Darkchild cohort Harmony "H-Money" Samuels and Dready (Lloyd Banks), Transition is still very much a distinctly British record which at times draws parallels with Tinie Tempah (particularly "Picture Me," a "Written in the Stars"-esque duet with former American Idol finalist Ace Young), and at others, early Dizzee Rascal (the minimal old-school rhythms of "Foul"). Indeed, the likes of "Every Gyal," a fusion of unsettling beats, Jan Hammer-inspired synths, and snatches of Jamaican dancehall artist Mavado's gruff tones, "White Lies," an atmospheric blend of clattering drum'n'bass, twitchy trance riffs, and soulful vocals from Dirty Money's Kaleena Harper, and the swirling tribal grime of teaser single "Flying High" could have all been lifted from his early pirate radio mixtapes, such is their uncompromising nature. Not that he's suddenly become averse to creating the odd chart-friendly pop tune, either. "Champion," a fist-clenching empowering R&B stomper which appears to borrow the piano hook from Bruce Hornsby's "The Way It Is," is only let down by Chris Brown's overwrought vocal melody, but Keri Hilson does much better on the string-soaked, rock-tinged "In the Air," as does Trey Songz on the Middle Eastern-flavored, midtempo "Take Off." Transition might not contain as many potential hits as its predecessor, but it's a convincing return to his underground roots which acts both as a defiant two-fingers up to the critics who labeled him a sell-out, and as a much-needed antidote to the dominant electro-pop sound of his contemporaries.