From their inception in
1967 up until the album
Rubycon in 1975, Tangerine Dream produced superb ambient music with primitive
synthesisers,
organs, and
guitar effects. During this stage their pinnacle was
Zeit, an early
illbient record which consisted mostly of held chords, detuned cellos,
wailing noises and drones. After the aforementioned Schnitzler and Schulze left the group, quite early on in its history, The Dream settled down to a line-up of Edgar Froese on synthesiser, Chris Franke on synthesiser, and Peter Baumann on synthesiser. This was the classic line-up and remained constant until the early 1980s. All three group members have had solo careers, on synthesiser.
After Zeit, the band produced Phaedra and Rubycon for Virgin Records in the UK, where the former was an unlikely top ten hit in 1974. Both records marked a shift towards a more rhythmic, melodic sound, whilst still remaining completely divorced from the mainstream. With this the group reached something of a dead end, however; after five years of experimentation they had taken the concept of formless ambient washes + a bouncy, echoed sequencer beat (with Mellotron) as far as it could go. Rubycon itself was essentially "Phaedra Plus".
Which explains why, by the end of the decade, the band changed tack entirely, becoming a relatively conventional instrumental electro-rock act. Although the group established a solid cult reputation and met with increased sales, their subsequent work was much less satisfying; simply put, their 1980s albums sound extraordinarily dated nowadays, calling to mind the music from Knight Rider (which was not by them) or Street Hawk (which was). The group also branched into movie soundtracks with a similar artistic trajectory, although their first, for William Friedkin's Sorceror, is highly recommended. Selections of their work were used effectively to score Michael Mann's odd, culty The Keep, whilst the group was also commissioned to produce music for the European release of Ridley Scott's Legend.
Since the mid 1980s the group has essentially been Edgar Froese and some hired help. They remain popular in Europe and have a passionate following on the internet; they still produce albums, all of which sound like the product of an old man attempting to sound like a young man (with inevitable echoes of Jean Michel Jarre). The 'gimmick' of using synthesisers exclusively is no longer novel, and it is ironic that, whilst the group's electro direction has been their most persistent period, it was their early spacey, ambient stuff that seemed more contemporary in the 1990s.
Outside the group, bear-like founder member and only constant Edgar Froese has released some interesting solo albums; as have former members Klaus Schulze and Conrad Schnitzler, both of whom are legendary in krautrock circles. Chris Franke did the music for the first few series of Babylon 5, whilst Baumann recorded one solo album and is now the world's leading Formula One driver and singer.