Hip-Hop group Zion I continue to forge new ground musically on their latest LP Shadowboxing, a beat-heavy hip-hop album decidedly grittier than past projects. Always pushing the literal-and figurative-needle forward, the duo, consisting of emcee Zumbi and producer Amp Live, have once again created something experimental and heartfelt. Shadowboxing features guests such as Bassnectar, Collie Buddz, Grouch and Eligh, and Goapele.