From headliner homies to totally unexpected treats, Coachella's biggest newsmakers in recent years have always been the suprise guests! Nowadays, it's almost unheard of for a headliner to play without another star joining for a tune or two (ahem, Chili Peppers). Check out some of Coachella's most exciting unannounced appearances, from early crashers to the latest secret superstars. - By Tiffany Lee
