Pink's fourth album is just as unsettled. Lead single "Stupid Girls," a kiss-off to young female singers less headstrong than Pink, is practically a genre unto itself; there's a lazy hip-hop beat, briskly strummed acoustic guitars, and the sort of tightly harmonized chorus we used to get from Destiny's Child. Elsewhere, she dabbles in "Since U Been Gone"-style tween-rock, hard-charging power balladry, arena-glam electro-punk, and piano pop à la American Idol. Despite the variety, Pink sounds at home through it all. Chaos she's used to, she seems to be saying; it's monotony that'd do her in.