Recently, Sigur Rós signaled their new release Valtari with the lead single "Ekki Múkk," which was also released as a 10'' for Record Store Day. The B-side to that release, the non-album "Kvistur," has now surfaced. Head below to hear the haunting track. [videoembed size="full_width" alignment="center"][/videoembed] Valtari is out 5/29 on XL. The "Ekki Múkk" 10'' is out now.