Perhaps titled with a knowing wink to its rather cluttered guest list, Boston hip-hop DJ Statik Selektah's fourth studio album, Population Control, features over 40 different singers, MCs, and DJs from the East Coast hip-hop scene, ranging from the established (Talib Kweli, Styles P, M.O.P.'s Lil' Fame), to those barely out of short trousers (15-year-old Game Boi). It's a testament to his production skills that despite the extensive array of collaborators, the follow-up to 2010's 100 Proof: The Hangover is a surprisingly cohesive affair which cleverly avoids drifting into random mixtape territory. Indeed, the slightly menacing, radio-tuning, opening title track provides something of a red herring, as other than the aggressive hip-hop break down that interrupts "You're Gone," and the chaotic homage to DJ culture on closer "A DJ Saved My Life," this is a predominantly chilled-out affair dominated by '70s soul strings, breezy jazz horns, chopped-up melodic samples, and laid-back rhythms. While the sheer amount of material to wade through means it sometimes feels like a bit of a slog, there is enough invention on display to justify the marathon running time. With its smoky muted trumpets, plinky piano chords, and soulful chorus, "New York, New York" could possible challenge Jay-Z & Alicia Keys' duet as the premier urban ode to the Big Apple; "Smoke On" merges a seductive bassline which could have been lifted from a Barry White record with languid beats and warm analog synths, while Nitty Scott MC and Rapsody more than compete with their male counterparts with the twinkling xylophones, scratched vinyl effects, and clattering percussion of the dreamy "Black Swan." Elsewhere there are nods to '80s synth pop ("Half Moon Part"), jazz-blues (Harlem Blues), reggae ("They Don't Know"), and falsetto-led R&B ("Play the Game"), while the highlight appears courtesy of "Down," a vintage slice of East Coast rap underpinned by a timeless gospel vocal sample and a simple, head-nodding military drum roll. Of course, Population Control could have been released at any point over the last 20 years, but while it's not going to change the face of the hip-hop scene, it's a classy and authentic old-school affair which effortlessly brings together two of its very different generations.