Billie Joe Armstrong's on stage meltdown, complete with cursing and guitar smashing, prompted the Green Day front man to go to rehab. This was supposed to be a busy time for the star, the first of Green Day's trilogy of albums, titled Uno! Dos! Tre! just released. Plus, Billie Joe as a planned appearance to mentor Christina Aguilera's contestants on the popular singing competition, 'The Voice'. His rep confirmed that he already recorded his part for the show, and the footage will air as planned.