Harper’s own ensemble projects cover a range of styles--the largely post-bop Onus Quintet, the free jazz-leaning Onus Trio, the intimate clarinet-piano duo Into Something, and the compositionally oriented C3 Project octet. As a sideman, Harper plays with Creative Opportunity Workshop (COW). He has held the clarinet chair in the Regina Carter Quintet and has toured through the US with Frode Haltli. He has performed concerts with Orrin Evans, Tim Warfield, Dee Dee Bridgewater, Carla Cook, Roscoe Mitchell, Dave Holland, and Uri Caine.