There core of the list is OK, I think, but it seems unbalanced overall... list making is tough, the mix of the canonical and the personal favourites, the important and the loved. Covering all the bases and getting a breadth of styles and, personnel and eras and the challenge is multiplied with something as amorphous as ambient, but it strikes me that there was no strong editorial voice here and there’s some glaring absences, strange repetitions and category errors as a result.
What is the definition of ambient that was used? Was it simply ‘without beats’, or ‘lacking structure’ or ‘rewarding as background music’? There’s stuff there that I would categorise as jazz, folk, soundtrack, experimental, classical etc… not strictly ambient. I know this is a tricky one, but in my mind there’s no way that Alice Coltrane album should be in there, or the John Hassel, or probably the Ernest Hood… its a subjective thing, and you could probably justify some of these using a wider definition, but on that basis you could do the same for ‘kind of blue’, or ‘meddle’, and even if you widen the net you should ensure you have all the hardcore genre stuff in there first.
So with that said, I reckon some huge, glaring, unforgivable omissions are Thomas Koner, Kevin Drumm, Elaine Radigue, but the biggest hole is the lack of the new ambient of the last 15 years or so. Oneohtrix shouldn’t be there, certainly not twice and not at the expense of the likes of Kyle Bobby Dunn Lawrence English, Stephan Mathieu, Ian William Craig, Deaf Centre, Olan Mill , Rafael Anton Issari, Celer, Illuha… theres much more Im sure, its been an incredibly fertile period.
In terms of foundation stuff - I like Pauline Oliveros as much as the next man, but two entries are perhaps suspect? I would’ve diversified with some other early electronic composers… Delia Derbyshire, some Tod Dockstader or Phil Niblock, maybe solo Stuart Dempster.
The 70’s - the Germans are reasonably represented, might have gone for more though… Ralph and Florian, Zeit by TD, Cyborg by Klaus Schulz maybe… Cluster and Eno, some Rodelious. David Sylvian might’ve deserved a mention alongside Hillage for the Night on Earth instrumentals... Oh, and some post punk, NWW’s ‘Lilith’. Time machine by Coil.
Geographically, Im a bit surprised by the lack of Japanese entries. There’s Ryosuke Miyata, Tomonari Nozaki, Toshiba Tsunoda, Yui Onodera, Masayoshi Fujita…
I don’t even want to start getting into soundtracks, but one thing from recent years that springs to mind is Mica Levi’s Under the skin OST. I think 2 stars of the lid is too much as well… there's a godspeed LP or 2 worthy of consideration and theres a ton of other post rock derived stuff that could’ve slipped in.
90’s chill out hasn’t aged to well to my ears but Dreamfish and Fax might’ve been worthy of a mention. I think If I had to pick some Namlook it would be the Definitive Ambient Collection vol. 2, though Id probably bin all the rising high chill out or die type stuff.
And last but not least theres some standout things from recent years. Alva Noto’s amazing xerrox Vol. 3, the last David Toop album, that Lau Nau LP, Before Nostromo By Stephan Mathieu, maybe even that Anthony Child album.
Oh, and they picked the wrong Ekkehard Ehlers.