Britney Spears’ sweat-soaked fourth album celebrates her fully grown status, with Madonna (teasing Brit on the sultry “Me Against the Music”) and the Ying Yang Twins (coaxing her crunk side on “(I Got That) Boom Boom”) partying in the VIP section. The slinky “Toxic” time-warps Bond strings and Bollywood glitz far into the future; that same high-tech touch gives "Showdown" and "Breathe on Me" their alien sense of funk. Spears' spellbinding performance on the crystalline, haunting “Everytime,” meanwhile, shows off her hard-won maturity.