Is it possible to be a sex symbol at age 68? Tina Turner might not have thought so eight years ago, when she officially "retired" from performing. But now she's back at it like Jay-Z, reportedly rehearsing eight to 10 hours a day. (And if you've ever seen her shimmy, you know that ain't no joke.) Rumors of a comeback album turned out to be just two new tracks on a greatest-hits disc, but does anybody going to the Sprint Center tonight really want to hear anything besides classics like "I Don't Wanna Fight" and "Proud Mary"? Bottom line: This diva still lives up to the title of her debut album, "Tina Turns the Country On."