Active since the mid-'60s, synthesizer experimentalist and musique concrète producer Asmus Tietchens has been a major influence on several generations of avant-garde electronic musicians and sound artists. Heavily inspired by Karlheinz Stockhausen, he has pursued "absolute music" through rigid formal exercises. His music is often harsh, alien, and abstract, but he's also recorded several albums of strangely playful material, including a handful of early-'80s Sky Records releases as well as later works as Hematic Sunsets. In addition to releasing over 100 recordings (including collaborations with Merzbow, Vidna Obmana, and Thomas Köner), Tietchens has taught acoustics at Hamburg universities since 1990, and he has written liner notes for dozens of albums released by the Bureau B label, particularly reissues of Cluster-related albums. Born in 1947 and based in Hamburg, Tietchens listened to German radio as a child and heard pioneering electric transmissions by the likes of Stockhausen and Gottfried Michael Koenig. He began recording his own home experiments in 1965 with crude reverb devices and picked up a MiniMoog several years later. Also influenced by atonal Krautrockers like Cluster and Faust, Tietchens met Okko Bekker and began a partnership that lasted for decades (Bekker has produced most of Tietchens' work). Tietchens participated in Liliental, a supergroup featuring Cluster's Dieter Moebius, engineer Conny Plank, bassist Hellmut Hattler, sax player Johannes Pappert, and Bekker. Their self-titled album was released by Brain in 1978. After Tangerine Dream's Peter Baumann heard a tape of his work, he produced Tietchens' debut album, Nachtstücke, released in 1980 on the French label Egg. His four albums for Sky during the early '80s (Biotop, Spät-Europa, In die Nacht, Litia) focused on surprisingly accessible electronic pop, though 1984's Formen Letzter Hausmusik (recorded for Nurse with Wound's United Dairies label) began a period of more abstract, concrète recordings that often use tape experiments as well as synthesizers. These include albums released by A-Mission Records, Discos Esplendor Geométrico, and Multimood. In 1986, upon invitation from the Goethe-Institute, he began traveling to South America to present lecture-concerts of his work, after which he began teaching in Hamburg. During the '90s, Tietchens recorded for dozens of experimental labels including Barooni, Staalplaat and Syrenia. In 2000, he initiated the Menge series of extremely minimal microsound works, initially released by Mille Plateaux sublabel Ritornell and later continued on Richard Chartier's Line imprint. In 2003, Die Stadt began reissuing Tietchens' early albums on CD for the first time, starting with the Sky releases. Tietchens wrote liner notes for these reissues, as well as reissues of Cluster-related albums. In 2012, Tietchens collaborated with Moebius for a self-titled album issued by Bureau B. The label subsequently reissued the Sky albums on CD and vinyl, with the bonus tracks from the Die Stadt reissues compiled as Der Fünfte Himmel. He continued releasing new works on labels such as Auf Abwegen and Stille Andacht. ~ John Bush & Paul Simpson, Rovi