Fans who have loved and respected Angie Stone for her maturity and understated musical approach might be surprised by “Tell Me,” a stomping club beat that features heavily auto-tuned vocals. But you have to give Stone some leeway — she's one of the most powerful and underrated female voices in contemporary music, and if she wants to write a song that will get her into the club with the youngsters, she's earned the right. In any case, the rest of Unexpected, Stone’s fifth studio album, features some of the singer’s most intimate material. “Maybe” and “Why Is It” address the hardship and frustration of relationships, but rather than sensationalize the issues, Stone treats them with the poise and slightly wearied wisdom of a 48-year-old woman. Because she isn’t working under the rules of today’s pop/R&B scene, Stone’s dance songs —“I Ain’t Hearin’ U” and “Hey Mr. DJ”— feel timeless, and have more in common with classic songs by strong female singers like Diana Ross and Lauryn Hill. The centerpiece is “I Don’t Care,” a brooding song about perseverance and self-empowerment that could be used as a mantra for the kind of smart, grown-up women for whom Stone speaks.