[Ygor]

No affiliation, but something I found on HN years ago was brain.fm:

https://www.brain.fm/

I've used it as a source of instrumental, good enough music. I'm not sure if the other "sciency" stuff actually worked. I didn't use it for a while now, partially due to a lack of macos native app.

[taraskuzyk]

Have been using this for about 3 years almost daily for reading, coding, and meditating sound if I'm in a noisy place.

I've found that compared to regular lo-fi playlists on Spotify my coding blocks have increased from 30 minutes to 50-60 minutes. Not sure what it does in terms of actual "productivity", but I can definitely spend more time working with it.