Record Rack

Since his fourth album (in stores Tuesday) describes a romantic metamorphosis--from oneness to two-ness, you might say--it makes a certain sense that singer-songwriter-guitarist Harper has transformed from solo artist to leader of a quartet. Like 1997’s “Will to Live,” this collection features bassist Juan Nelson and drummer Dean Butterworth (joined by percussionist David Leach), as well as broad-ranging explorations of Harper’s folk-rock-jazz-soul-pop.

Love is the glue that binds these tunes, which travel from molasses-like soul (“Alone”) to vitriolic rock-funk (“Less”) to Stones-y twang (“Burn to Shine”) to Gram Parsons-style spiritual folk (“In the Lord’s Arms”).

But as is frequently the case with Harper’s work, there’s precious little urgency here. The ballad “Show Me a Little Shame” is heartfelt, but its begging-demanding dynamic deserves a more fiery treatment, perhaps a soul-ripping wail or two. Then again, the more driving “Please Bleed” sounds like a musty Nirvana imitation, while the generic rocker “Forgiven” is lofty and dull.

More frustrating, Harper’s songwriting continues to improve, and he truly shines on the sensual R&B-pop; tune “Steal My Kisses,” which has real energy along with the casual swing he prefers. Too bad he couldn’t reconcile those apparently divergent tendencies more often.