Compilation series are usually a fine source for digging the latest and greatest in underground rap, but the fourth volume in Om's Deep Concentration series deserves a special place even among the classics. J Boogie, the master of ceremonies (and an MC on one track), gives this set a funky, old-school feel, dedicating the record to earthy breaks and mile-wide hooks guaranteed to paste smiles on the faces of hip-hop fans. The lineup is stellar as well, including several excellent collaborations -- People Under the Stairs meets J Boogie himself on the moving-and-grooving "Movin to My Beat"; the turntablist DJ Format, veteran of several Return of the DJ compilations, backs Akil and Chali 2na from Jurassic 5 with a production that surprisingly equals most any Jurassic track; J-Live cuts it up with the Nextmen, a young but talented British production crew; and Planet Asia, one of the best rappers on the West Coast, meets turntablist Mista Sinista over a seminal Architect production. Surprisingly, a few of the new names are no less impressive, led by Crown City Rockers and Swamburger. ~ John Bush, All Music Guide