While recording her self-titled third album, Britney Spears was also filming her first movie, Crossroads, a coming-of-age story about three friends who embark on a road trip after high school graduation. Just as her character does in Crossroads, on Britney, Spears navigates love, independence, and self-doubt in the gray space between childhood and adulthood. “I know I may be young, but I’ve got feelings too/And I need to do what I feel like doing/So let me go and just listen,” she urges on the opening track and lead single “I’m a Slave 4 U.” Backed by slinky drums and woozy synths, Spears’ breathy invitation to “dance up on [her]” introduced a more mature sound and image, far from the bubblegum pop of “...Baby One More Time.” This shift happened as Spears took a bigger role in the creative process, co-writing six of the album’s songs. Inspired by hip-hop and R&B, she’s said she wanted the music to be “nastier and funkier” and recruited some of the genre’s best architects to get there. The Neptunes (Clipse, Kelis, JAŸ-Z), in addition to “I’m a Slave 4 U,” crafted the titillating “Boys,” on which Spears beckons a would-be suitor to turn the dance floor into their “own little nasty world.” Rodney “Darkchild” Jerkins (Brandy, Beyoncé) is behind the growling “I Love Rock ’N’ Roll,” a cover of Alan Merrill and Jake Hooker’s 1975 song made famous by Joan Jett & The Blackhearts. Spears is at her most defiant on the anthemic “Overprotected,” tired of being told what to do and ready to live on her own terms. But she drops her armor on the Dido-co-penned “I’m Not a Girl, Not Yet a Woman,” which captures the growing pains of growing up: “All I need is time, a moment that is mine,” she sings, “while I’m in between.” With the 25th Anniversary Edition, Spears reopens the vault. In addition to a pair of remixes, it features previously unreleased fan favorites like the kiss-off “She’ll Never Be Me” and the conflicted “Am I a Sinner.” There’s also a newly unearthed song: “My Big Secret,” a dreamy, stripped-down R&B outtake from her sessions with The Neptunes.