I've got a nice "Relaxing" playlist on foobar I'll put on occasionally while gaming or stressed out internet browsing. My criteria for it is usually tracks or albums that I can listen to without getting too excited, not so sure about the not too sad criteria I find those can be cathartic.
Every now and then I'll listen to music while playing games, but more often I'll multi-task and watch something else while also playing some game. The only problem is that it can be kind of hard to do and rather distracting when playing games that are very heavily story based with a lot of dialogue, so I usually do that when playing less taxing games like RimWorld, Minecraft, or Terraria, or even some platformers. As far as music goes, I really like listening to touhou bossa nova stuff and will usually turn off the in-game BGM to listen to it while playing. I do that less often, though.
I attached her image because I thought she looked a bit like Yuno.
I go for more instrumental jam type stuff when im playing games or doing work or something, lots and lots of Grateful Dead. the music works really well for going in and out of paying attention as a lot of times the great moments take some time to build to. also a lot of jams that meander around without really grabbing you at any one time, its music that flows and feels like it could go on forever which is why I think it’s perfect for these types of situations
I don't know when it happened exactly, but I mostly stopped listening to music when I'm doing things that require thought. When I did, though, I remember that lyrics were definitely way too distracting. Instruments are good. Calming, soothing instrumentals are the best.
Actually, I'm going to turn on some Atelier music right now and see how it affects my posting..