Anyone who's spent time at the coalface of kosmiche that is the 130+ strong Tangerine Dream back catalogue will know there's a hell of a lot of new age guff, a decent amount of good stuff and loads of new age guff that's oddly good - as my mate Martin calls them, 'borderline records' that you keep returning to for reasons unexplained. I won't attempt a history-of-the-cosmos-according-to-Edgar Froese here, if you want that you'll need to peer past the dodgy nebula CGI and Spinal-Tap-isms that pepper the enjoyable (but flawed) TD documentary Revolution in Sound, which was on a limited cinema run over the last bit of 2017. Those hardy enough to emerge the other side of the trip might agree that it basically breaks down into three periods. Part one: mk1 days of Edgar Froese, Chris Franke and Peter Baumann (1967-1978) making analog rollers in der europäische tradition. Next, 1980s TD which saw Baumann replaced with Johannes Schmoelling (1979-1985) for the Hollywood years. I'm not sure if it was the external (read: financial) influences on the band, or that Schmoelling had a particular influence on the sound, but the releases during this second period seem quite focussed - see Thief, Risky Business, Firestarter, Poland, Exit etc. By the time Schmoelling and Franke had left in 1987 the rot had well and truly set in for the third act and by 1988/89 it falls off a cliff in terms of quality. I wouldn't even count anything past Franke's exit as TD really, it's Froese and a slick touring machine of hired guns. The fact that a Tangerine Dream live show has just been announced in London with no original members is off-the-charts batshit, but it gives you an idea how long they have existed outside of the mainstream. Anyway, here's a few gems (TD and solo stuff) and a a few 'borderline' bits to make your mind up on.

Dr Destructo, 1981

Long before Stranger Things and the rest of the nostalgia industry pissed in the punch, Michael Mann made violent, brooding and totally original films like Thief and Manhunter with absolutely killer soundtracks - 1981's Thief is a must-watch. Imitators beware.

Charly the Kid, 1984

The ironic thing about that whole ‘it sounds like the soundtrack to a movie that hasn’t been made yet’ observation that infests YT comments under IDM tracks is that, in the case of TD, there was a period where they knocked loads of brilliant stuff out in the studio without ever seeing the film - this is a prime example. No hard edges on this one – drums mixed so weirdly quiet they tickle rather than thump, but it's up there with the best material from the Risky Business soundtrack. Firestarter is classic mid-period TD.

Cloudburst Flight, 1979

I think this was when the group were a Froese / Franke two piece. It's pretty lean and riff-heavy as a result. One of those records where you imagine they smoked a million fags making it.

Kiew Mission (Live), 1982

Don't know who the breathy babe delivering a warning of impending global nuclear apocalypse in Russian is, but this live version of Kiew Mission is tight.

Live at Coventry Cathedral, 1975

They got panned by the Vatican (not kidding) for a gig in a French cathedral where somebody pissed against the pillars. Thereafter, TD were welcomed into the Anglican church for egg & cress sandwiches and mescaline.

Dolphin Smile, 1986

Not quite the jetski-round-Pebble-Mill-Studios unprotected sax of the (frankly atrocious) Melrose-era releases on Private Music, but this one is definitely in hot water – it’s called Dolphine Smile for starters - but then if you've got this far down this piece, who are you kidding? Makes an early appearance in the new age bells and smells classic bootleg Tangerine Tree 38 from Berlin '87. Definitely borderline.

White Eagle, 1982

It's the end of the world, you're dying from radiation sickness in the fall-out shelter so you boot up the video link to call loved ones and utter a last word.... but what's that? Is that a fucking ken burns effect photo montage of eagles with Tangerine Dream playing in the background?

Poland, 1983

TD were never sexy – but in this live show from Warsaw, 1983 they were definitely cool. 808 boom-clap / trancey arpeggios / phantom ballerina visuals and a soviet McDonalds. Its mind blowing that even in communist Poland of the early 80s, where TD were presumably deemed to be ideologically ‘sound’, music this noncommercial played to a crowd of thousands in -15C temperatures. Hang on past the proggy bit for the warm bath ambient bit.

The End (The Keep OST), 1983

Out of the the swinging-dicks competition that was the making of supernatural Nazi horror flick The Keep (another Michael Mann picture) comes some real fan favourites. The film’s a real pig, an almost unwatchable mess that suffered from a brutal edit which cut the film’s original 3 hour+ run time down to the length of a football match. Still, the fact the soundtrack remained unreleased at the time of Froese’s death, aside from a small run of CDRs at concerts (why, of course), adds to the murkiness of the whole thing.

Pinnacles, 1983 (Edgar Froese solo)

OK. So I'm going to put a couple of not strictly TD bits at the bottom - but let's face it, you're not going to read another one of these for a while and I'm unlikely to be allowed to write one again so here we are. It's a toss up between this one and Epsilon in Malaysia Pale for the pick of Froese solo - classy stuff.

The Lawnmower, 1988 (Johannes Schmoelling solo)

'The Zoo of Tranquility' is, in my recollection, a concept record about automata. I think that probably says all you need to know about Johannes Schmoelling's state of mind post-TD. Weird and wonderful record, showed up on a nice Chee / Young Marco set a couple of years back too.