Jon Thor Birgisson became known on the indie rock scene as a vocalist and guitarist for the Icelandic post-rock band Sigur Rós, formed in 1994 in Reykjavík, the capital of Iceland. An open homosexual, he adopted the name Jónsi for his projects outside Sigur Rós.

In 2009, Jon Thor Birgisson released an album (Riceboy Sleeps) in partnership with her boyfriend Alex Somers, a project named Jonsi & Alex.

Jónsi's first solo album came out in 2010. Titled GO, the album was released by XL Recordings. Ten years later, the musician released the second, Shiver, album featuring collaborations by Elizabeth Fraser from Scottish band Cocteau Twins and Swedish singer Robyn.