I like any of the Nujabes albums. He makes chilled, mainly instrumental, hip hop music.

Something semi ambient, preferably without lyrics: Tycho, Bonobo, Nujabes

Any rando lofi channel on YouTube/Spotify/Online Radio Stations

In a Space Outta Sound by Nightmares on Wax

Autechre’s NTS Sessions. All of them work great, but start with the fourth one.

Here’s a tip I picked up somewhere. Make a playlist. An hour or two worth of music. ONLY listen to it when you’re studying. I’ve found my brain just blocks it out after a few times through, but it triggers my subconscious or something. As in, if I’m not feeling like studying, I put it on and my brain just goes,“OK, it’s time to study.” I change it up when I’m starting a new long task (writting a new book, starting a new semester, whatever). At first, I find myself listening to it, but it doesn’t take much repetition for it to fade into the background.

Not really a album but MyNoise.net has a lot of good generators for background noise. Radio Free Fedi’s Comfy channel also is great for chill study music, and it only plays indie artists that have Fediverse accounts with links to the artist support pages where you can either buy their albums (or songs to build your own piecemeal) https://radiofreefedi.net/.

Every album by the band Can

Piano Phase by Steve Reich

Bonobo - Dial M for Monkey

I just added a bunch of classical to a playlist and then removed the occasional piece I found distracting. I still use that playlist when I need to focus.

Use something mellow in a different language from your own, it is less distracting.

I like to listen to brasilian Bossa Nova like this Getz/Gilberto Album

Or something without lyrics like Yiruma if you like Piano music.

Anything from Hammock. The older albums mostly.

Robot Science

Anything by Erang. If you are into medieval mythical themed hymns.