If Jazmine Sullivan’s great twin themes are vulnerability and victimhood, then a lack of experience is her Achilles’ heel — or it was as of 2009’s Fearless, a mostly unremarkable debut that somehow shifted enough units to earn the Philadelphia-bred R&B star a gold record. For Love Me Back, Sullivan made some changes: she shook up her go-to songwriting brain trust, let her hair down, cherry-picked beats that complement her voice’s bold, boisterous timbres, and scaled back the emotional extremism. Less busted car windows, Jennifer Lopez-in-Enough moments, and cut-rate melodies; more harmonically satisfying productions. So on “Don’t Make Me Wait” — an upbeat, La da Mystro banger that all but quotes Madonna’s “Lucky Star” — Sullivan gets her saucy bad-girl on, while gospel-in-tempo-and-temperament “Excuse Me” takes spousal appreciation to church. Elsewhere, the Missy Elliott co-produced, New Jack-swung “Going In Circles” is so richly bombastic that it makes being stuck in a bad relationship seem almost fabulous even as it tearily jabs angry fingers. But Back’s most welcome surprise is “Redemption,” a mixed-metaphor romance noir that can’t decide if it’s straight Maury Povich trash or code for drug addiction.