The experimental Icelander is one of several artists who have confirmed they are playing at this year's event and she is lining up an ambitious show.
She told BBC 6Music: “We have just started rehearsing and that is why I am in Iceland right now, we have a massive band, a ten piece brass band, we are rehearsing full on now, and I am kind of very excited but also very nervous which is a good thing.”
Among other contributors to her show, said the singer, will be percussionist Chris Corsano, collaborator Mark Bell and an Icelandic-Chinese concert pianist.