Album number four for this popular electric jazz quartet heralded a significant change in personnel; Lee Ritenour exited to run his new record label and Larry Carlton stepped in to fill the guitar slot. On paper, this switch would seem to signal a tougher, funkier edge for this band -- and Carlton's playing on the album is somewhat more rhythmic and upfront than that of his predecessor. But in practice, little has changed for Fourplay; their forte remains smooth-running, polished mood jazz with a gentle rock beat, soft-textured vocals, and good-natured interplay. Indeed, Carlton emphasizes the idea of continuity by adopting Ritenour's velvety octaves and generally taking a restrained approach. Such a concept, though, generally stands or falls on the quality of the material -- and the compositions of Bob James, Nathan East, Harvey Mason, and Carlton are mostly wanting in memorability, although the CD picks up speed near the end with James' funky "Vest Pocket" and Carlton's catchy, looping "Swamp Jazz." Also, sometime guest vocalist El DeBarge returns with a pro forma falsetto performance of another Marvin Gaye song, "Sexual Healing," which neither transforms the tune nor erases memories of its composer. Though 4 was recorded well before Fourplay's first live performances with Carlton in June 1998, their early gigs mostly confirmed the impression left by this low-key album; no one wants to rock this lucrative boat.