alt-J is an English indie rock band that consists of vocalist and guitarist Joe Newman, keyboardist and bassist Gus Unger-Hamilton and drummer Thom Green. Gwil Sainsbury was the band’s bassist before leaving the band in early 2014.

Formed at Leeds University and signed to a label in Cambridge, UK, the band originally made songs on Garageband before releasing them under the pseudonym ∆.

∆’s name takes a little explaining. Pronounced alt-J, the delta sign is inserted when you press alt and J on a Mac keyboard.