American musician and actor. He is best known for being the lead vocalist, guitarist, and primary songwriter of the rock band Green Day, which he co-founded with Mike Dirnt in 1987. He is also a guitarist and vocalist for the punk rock band Pinhead Gunpowder, and provides lead vocals for Green Day's side projects Foxboro Hot Tubs, the Network, the Longshot and the Coverups. Armstrong has been considered by critics as one of the greatest punk rock guitarists of all time