Alt-J, also known as delta, is an English indie rock band formed in Leeds in 2007. The group consists of Joe Newman on guitar and vocals, Thom Sonny Green on drums, and Gus Unger-Hamilton on keyboards and vocals, with Gwil Sainsbury as a former member. Their debut album, An Awesome Wave, won the 2012 British Mercury Prize. The band's second album, This Is All Yours, reached number one in the UK. They followed with Relaxer in 2017 and The Dream in 2022. Alt-J is known for their distinctive sound blending indie rock with experimental elements.