The new "Bloom" strips away the song's driving bass line and discombobulating percussion, focusing instead on a disparate piano melody, an undercurrent of strings and Thom Yorke's vocal.
After the slow build, the track unfurls over its final minutes as Zimmer's lush, cinematic contributions are breathed into "(Ocean) Bloom." The song was paired with a "prequel" video for Blue Planet II, featuring footage that won't appear in the seven-part series when it premieres later this year on the BBC.
In a BBC interview revolving around the track, Zimmer and Radiohead's Yorke and Jonny Greenwood talked about the collaboration, with Yorke revealing that the original Blue Planet series inspired "Bloom."
"It sort of seeped into my subconscious. I found myself dreaming of these creatures quite a lot," the singer said. "When we came to do all those weird recordings for The King of Limbs, it must have been in there. It started with Colin [Greenwood's] bassline and 'Open your mouth wide.'"
Zimmer added, "In a funny way, I was trying to be respectful and not ruin the song, if you know what I mean. If somebody hands you somebody else's work, there's responsibility and respect that comes with it."
Yorke also explained why Radiohead became involved in the project. "The fact that this TV series is coming out at this moment, I hope rekindles our love of the oceans and our desire to understanding, really, our relationship to them," Yorke said. "Like, 'This is bigger than you. This is bigger than you.'"