Britney Spears makes a heroic effort to stave off oblivion with her pivotal new fourth release, "In the Zone." That is, Spears and her army of collaborators, producers and guests make a heroic effort.

The 21-year-old is finally a full-fledged adult, and she's no longer counting on fickle pre-teen/early teen girls to drive her success. Instead Spears makes overtures toward a more mature pop audience and a hip-hop/urban audience and a dance audience.

"In the Zone" is easily Spears' best album - which isn't saying much given the dubious manipulations of her suspect vocals and the heavy-handed, formula-minded production of her previous releases. Yet "In the Zone" is more than just her best album; it's actually pretty good.

The appeal has little to do with first single "Me Against the Music," a duet with Madonna that sounds more like an overstimulated publicity stunt than a congruent song. Also, the overblown urban cuts "(I Got That) Boom Boom" (featuring the Ying Yang Twins), "Outrageous" (penned by R. Kelly) and "The Hook Up" (featuring dancehall vocals by BUD) are serviceably boisterous, though not really the best niche for Spears.