Cluster was the pioneering German duo of Hans-Joachim Roedelius and Dieter Moebius. Formed on the cusp of the 1970s, they were a part of West Germany's nascent Kosmische Musik scene. The group would use restrained improvisational techniques similar to Gruppo Nuova Consonanza, working with both electric and acoustic instruments (organ, guitar, tone generators, cello, etc.) to create a singular sound that Julian Cope called "a huge beating heart, planet-sized and awesome."

Following the release of Cluster II, the duo relocated to the village of Forst where they built a home studio and began to collaborate with like-minded artists such as Michael Rother and Brian Eno. 1974's Zuckerzeit, Cluster's first album made in their countryside studio, marked a major shift in their music from experimental noise to avant-pop. "Hollywood" starts things off with infectious loops, analog drum machines and sweeping synth. "Caramel" seems to pick up the pace even more; its sugary groove promptly dissolves into a sea of ethereal keyboards, amorphous layers and sparse chords.

For Zuckerzeit, Roedelius and Moebius developed the tracks individually. They recorded in separate rooms on different days, although each piece flows into the next seamlessly. While Rother is listed as producer on the original Brain release, he was reportedly not present at the sessions and simply loaned the band some equipment.

Bringing together Cluster's haunted melodic sense and motorik rhythms, Zuckerzeit reveals not only how much the band grew from their experience in Harmonia, but also how instrumental they were in their later collaborations with Eno.