On Back to Black, her second album and U.S. debut, singer-songwriter Amy Winehouse defines her own tradition. With a deeply personal touch, she commands settings that meld torchy doo-wop era ballads, soul and girl-group slammers, and current hip-hop winners. Winehouse, already famous in her native England for reckless, tipsy behavior, topped the charts there with “Rehab,” a construction that wraps her protests that Ray Charles and Donny Hathaway are more help than a clinic could be in a forthright tribute to early-’60s radio that does the Ronettes and the Drifters proud. Despite the buzz from that instant anthem, Back to Black doesn’t shy from the heartbroken — and not just in the “Me and Mr. Jones”’ complaint that she missed a Slick Rick show. The title track brings the real pain, one more in an album of performances that certify the 23-year-old Winehouse as an undeniable master.