Metallica and Green Day may be international rock gods but that doesn't mean they forget where they came from.
After Green Day front man Billie Joe Armstrong was forced to cancel all upcoming shows to address a problem with substance abuse, fellow Bay Area rockers Metallica not only filled in for the band at a concert, but paid tribute to Green Day, as well.
Metallica headlined the 2012 Voodoo Music Experience in New Orleans in Green Day's place over the weekend.
According to MSN, Metallica guitarist James Hetfield joked with the crowd, chanting "We! Are! Green Day! Except a little bit taller!" as the band took the stage. But later, the nine-time Grammy Award-winner spoke seriously about the situation.
"This one's for Billie," he said, before launching into his hit song, "Battery."
During the encore, the band again honored Armstrong, playing the opening riffs of Green Day's "American Idiot," while the crowd sang along.
"He's there getting help," said Hetfield, per Live 105. "Getting it sorted out. We're here stepping up for him, hoping he gets it together, 'cause the world needs him."
Check out Metallica covering "American Idiot" in Loudwire's clip below: