A glamorously gaudy, self-made, post-modern diva stitched together from elements of Madonna, David Bowie, and Freddie Mercury, Lady Gaga is the first millennial superstar. Mastering the constant connection of the Internet era, Gaga generated countless mini-sensations with her style, videos, and music, cultivating a devoted audience she dubbed "Little Monsters." But it wasn't just a cult that turned her 2008 manifesto The Fame into a self-fulfilling prophecy: Gaga crossed over into the mainstream, ushering out one pop epoch and kick-starting a new one, quickly making such turn-...