'Zeit' was released in 1972, and originally consisted of two vinyl discs containing four pieces of music in total, two per disc, one on each side. Each piece of music is 17-18 minutes long and, in common with the group's earlier output, formless. Only 'Plejades' has any progression - it starts off with a sick-sounding cello quartet playing dissonant notes and then moves onto organ and synthesiser - the other songs start as they finish, with electronic drones, held notes, casual guitar strums and lots of electric organ. There are no tunes, no percussion, no time signatures and no rhythm other than that of the stylus gliding over vinyl.
The music is similar to Brian Eno's ambient experiments of a few years later, but much less airy. Zeit is murky and oppressive and, as background music, it creates an air of unease and despair; it is the first 'illbient' record. It was also the album the group's career had thus far been building up to - their next album, Phaedra, was much bouncier.
The cast list is interesting. Apart from regular members Edgar Froese, Chris Franke and Peter Baumann, the guest musicians included Florian Fricke of Popol Vuh, whilst the album was engineered by Dieter Dierks, who made his name producing The Scorpions, a very different krautrock band.
The album has been re-released on CD a number of times, although to modern ears even this remastered re-release (with the original packaging and an essay by Julian Cope) is very hissy, as it was multi-tracked and bounced down rather a lot (and furthermore it is supposed to be played quietly).