Brian Eno's second album collaboration with Dieter Moebius and Hans-Joachim Roedelius of Cluster consists of slow-moving instrumentals full of repeated synthesizer sound patterns and sustained guitar notes in the ambient style familiar from Eno's collaborations with Robert Fripp and albums of his own, such as Discreet Music. One song, 'Broken Head,' features recited vocals by Eno, and on another, 'The Belldog,' he sings. On 'Tzima N'arki,' his vocal is turned backwards.

原版於1975年9月發行。