You probably best know Shia LaBeouf for his star turn in the the 'Transformers' trilogy, or perhaps his role in 'Wall Street: Money Never Sleeps,' but the movie star recently made a bit of a more low key appearance when he turned up in the new video for 'Fjögur Píanó,' a song off Icelandic post-rock outfit Sigur Rós' latest album, 'Valtair.'

Sigur Rós are often cited for composing music that would work well as the soundtrack to an art house film, and 'Fjögur Píanó' is no different. The title of the sprawling track translates from Icelandic to English as "four pianos," and, not surprisingly, the instrumental composition sounds as if four pianos are playing in slow motion along to an Ambien drone --  eight minutes of twinkling, blissfully transcendent ambiance.

The accompanying video, which is helmed by 'Bombay Beach' documentarian Alma Har'el, is amusing, confusing, confounding and emotionally stirring all at once. There definitely seems to be a plot, although trying to nail down exactly what's going on proves to be a challenge.

The opening screen relays some basic info -- the piece is the third in a series called the "Sigur Ros mystery film experiment," and the NSFW aspect is due to "scenes of nudity" -- but beyond that, it's really up to you. Scenes feature interpretive dancing, cars cruising underwater, Shia LaBeouf drawing on nude bodies, mild violence and other visual delights.

"At first I didn't know what to make of the video, because it is so full of ideas and confusion, but now I completely love it," says bassist Georg Holm. "It seems to have no beginning and no end, and just makes you think about what might and might not be going on. It's a puzzle, and I think it's absolutely amazing."

“[It's] about addiction to drugs, or sex, or anything -- and how you get stuck in a cycle,” Har'el tells the Wall Street Journal. “For me, it’s about not knowing how to get out of something without causing pain to somebody else.”

Watch the Sigur Rós 'Fjögur Píanó' Video (NSFW)

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