Just Be Free (2012)

For those who've ever wondered what Aguilera was doing four years ago, here's the answer: applying her nascent pipes to low-budget, cookie-cutter house tracks. As she informs us in her disclaimer-heavy liner notes, these recordings (the release of which she initially attempted to block) were ''a possible stepping stone'' and never intended to come out. Now we know why. Historical reference point: The way the 14-year-old Aguilera tepidly growls lines like ''Why don't you stay with me tonight?'' clearly set the stage for her teen-jailbait persona.