Okay, I'm gonna try to dunk on everyone here who's already posted, by combining actual NASA Apollo mission recordings with perfectly-matching ambient music:

https://somafm.com/missioncontrol/

Listen to it and chill, mateys...

In my spasmodic search for non-AI ambient channels I finally docked on the calm spaceport manned by Martin Stürtzer and his cat Neptune

https://youtube.com/@martinstuertzer

There's plenty of variations of this out there, but it's gotta be the Star Trek warp core droning.

https://youtu.be/D0w_ixXDCtw

Why use YouTube when you can make and customise your own? I know someone sent me one a while ago that looked pretty good, just googled and found this one that is open source. https://moodist.mvze.net/

Not sure if there are better ones, might be something to look into.

Cinemood. Just search spy jazz. Good stuff.

Not YouTube but no ads:

• https://ambientsleepingpill.com/
• https://ambientmodern.com/
• https://amambient.com/

All three have streaming links and Spotify channels.

For chillwave/synthwave ambient music, I absolutely love:

https://youtube.com/@OdysseusOfficial

and

https://youtube.com/@INEXED

This musical composition drops beats like there is no tomorrow: https://www.youtube.com/watch?v=nMfPqeZjc2c

But in all seriousness, I do like this channel: https://www.youtube.com/channel/UCwVQIkAtyZzQSA-OY1rsGig

you know how digital broadcast stations have those .2, .3, .4, etc. I really think they should think about using at least one toward ambient sounds over reruns of stuff.

Lofi girl is pretty good