It's British, bitch? Trying on a Cockney accent to enhance her ferocity, Britney Spears makes "Work B**ch!" an unexpectedly playful preview of her forthcoming eighth studio album. It's a welcome change from the roboticized erotica of 2011's "Femme Fatale," which seemed to be more of a showcase for executive producer Dr. Luke than for its vocal star. Teaming with Will.i.am this time around, however, Spears sounds more engaged than she has in years.