Krautrock and ambient electronic music pioneer Hans-Joachim Roedelius was one of the foremost voices in his field, starting with work in the groundbreaking group Cluster in the early '70s. His spacious, winding synth tones in that band's more rhythmic output gave way to a prolific solo career that often highlighted the more playful or curious voicings of his instrumental mastery. Lloyd Cole, former frontman of U.K. pop stars the Commotions, fell in love with Roedelius' heaven-sent synth work early on, eventually emulating it with his 2001 album Plastic Wood and then going so far as to collaborate with the man himself on 2013's airy collection Selected Studies, Vol. 1. Cole combed the archives of Roedelius' solo work to present the second volume of his Kollektion series, pulling together 15 tracks of celestial beauty, icy disdain, and meandering ambient pop as only Roedelius can do it. The collection focuses on output from the '70s and '80s, pulling tracks from the many albums of stripped-down minimal grandeur he produced for the Sky Records imprint. This is where the best material on Kollektion 02 lies: in the wandering feel of "Wenn Der Sudwind Weht" and the submerged rhythmic pulse of "Sonnengeflecht." Elsewhere, "Ampfer" takes a look into the more melancholic side of things with its sad abnd searching tones; it's one of many sketches Roedelius quickly recorded as part of his Self Portraits series which spanned the '70s and beyond. Work exploring less spacy styles is represented here as well, with the circus-like organ bleats of "Cafe Central" and the dark and pushy synth stabs of "Aufbruch." Expertly curated by Cole, this collection highlights Roedelius' gifts and shows the line of their direct influence on Bowie, Eno, Aphex Twin, and eventually an entire spectrum of electronic artists indebted to his graceful, minimal approach.