Songfacts®:

• This track from Bjork's seventh album Biophilia finds the Icelandic singer warning us that only rebirth can save us now. She's accompanied on the song by Zeena Parkins' silvery harp and a siren choir. It contains different musical cycles that repeat throughout the song. The tune was released on iTunes as a solo promo-single on September 6, 2011.
• Biophilia finds Björk attempting to break the typical 4/4 time signature and this song features 17/8 times bars.
• Biophilia is billed as the world's first "app album" and this track is accompanied by a song and music sequencer inspired by the similarities between the cycles of the moon and tides and cycles in music.
• Bjork attempts on Biophilia "to unite the scientific and the emotional." She explained to Stereogum that this song, for instance, "is very melancholic and about rebirth and the lunar cycles but it's also just about the math of a full moon." The Icelandic singer added that she wanted the music to, "weave seamlessly into science, a natural element, and musicology."