Watch :: Sigur Rós debut new song at Primavera Sound

Fifteen years after they first played Barcelona, Icelandic post-rockers Sigur Rós returned last night (June 4) to play at Primavera Sound Festival.

As the opener to their six-song set - which also included 'Starálfur', 'Sæglópur', and 'Kveikur' - they also premiered a new song, 'Óveður'.

Check it out above.