Two members of Sigur Rós (Holm and Dýrason) working with Icelandic composer Hilmarsson and Georg Holm’s brother Kjartan (touring guitarist with the band) on the soundtrack to The Show of Shows – a documentary by Benedikt Erlingsson on vaudeville, circuses, and carnivals that aired on the BBC as part of Storyville (unfortunately listed as “not currently available”).
It’s beautiful atmospheric music.
My copy via Vinyl Destination in Lowell MA