It's always an exciting time whenever we hear about new Sigur Rós material but, alas, that isn't happening today. However, it's the next best thing, as the band have put up a whole bunch of unreleased demo tracks (albeit already released in another form) from their earlier years onto their SoundCloud page (via Pitchfork and Consequence of Sound).
What we have is a svefn-g-englar demo set from 1999, ágætis byrjun manipulations and ágætis byrjun demos. Listen to all three of these sets below and enjoy them, above all.