Cluster - Konzerte 1972/1977
(Bureau B)

Although they get lumped in with the always dubious Kraut Rock tag, Dieter Moebius and Hans-Joachim Roedelius (aka Cluster) were far more experimental and chaotic putting themselves on the outer fringes of the Kosmische movement. Their early studio records (such as Cluster and Cluster II) were improvisational in nature with a genuine roughness that was uncharacteristic among their contemporaries. What they were doing was more proto-noise for the textures and sounds they were emitting and perhaps even proto-punk in ethos due to their utilization of primitive gear and synths. 
While they did perform live quite frequently, rarely have any been released to the public, save one of the tracks on Cluster II. Konzerteremedies this with 2 side-long performances from 1972 and 1977. Side 1 is taken from Fabrik, Hamburg 1972 (which is the same performance used on Cluster II) and it truly shows the harsher side of Cluster. Crude synths careen on either side of the spectrum while howling guitar feedback vibrates throughout. They later embrace the din and black afterglow as the rapturous noise settles into a sullen hum.
Side 2 was recorded live at a science fiction festival in Metz, France 1977. While less dynamics are at play, Moebius and Roedelius create something slightly prettier while still engaging in a sort of sonic decay. Sustaining organ chords intermingle with guitar vibrato and slight traces of squall in what will nicely forecast their soon to be released, (or perhaps just released), collaboration with Brian Eno, Cluster & Eno. 
The production and sound quality of these live recordings is excellent and nicely documents Cluster on stage. Konzerte is certainly a worthy piece to own for any German obsessive (such as myself) and a great record to snag if you missed the Cluster box set which until now, was the only place to get this LP. Includes CD version as well! (Dom)
Check out a track here.