Alt-J (stylised as alt-J, real name Δ) are an English indie rock band formed in 2007 in Leeds, by Joe Newman (guitar/lead vocals), Thom Sonny Green (drums), Gus Unger-Hamilton (keyboards/vocals) and Gwilym Sainsbury (guitar/bass). Their debut album An Awesome Wave was released in May 2012 in Europe, and in September 2012 in the United States, and won the 2012 British Mercury Prize.