Green Day singer Billie Joe Armstrong melted down in a big way during the iHeart Radio Festival in Las Vegas last month, spewing F-bombs, smashing his guitar and seemingly seething with anger due to a shortened set. Turns out the frontman had fallen off the wagon, and he promptly went to rehab to address his issues. The fallout occurred right around the release of '¡Uno!,' the first album in a planned trilogy, and resulted in canceled appearances and lost promotional efforts. Ain't no thang, according to bassist Mike Dirnt. The band agreed its friend's life had to come first and promoting the album had to come second.