When I really need to concentrate I put on music in a foreign language. Mainly German because I've found a lot of German bands I like. Some of my favorites that sing mainly in German:
Either ambient instrumental music (lots of Brian Eno) or any music that I know all the words to (so that my brain doesn't have to actively process the lyrics).
Depends on the kind of concentration. If I'm programming or doing some kind of math, I want fury. I'm reaching for Slayer or Megadeth or the Doom sound track. Nothing like Angel of Death to plow through something.
If it's more contemplative, power ballads. Something I can sing without focusing on it. I Want to Know What Love Is. Keeps pace, but it's more emotional. Keeps me in that thoughtful place.
Cooking, woodworking, cleaning. Something active but not on the whole fast. Heavy metal, southern rock, or blues. Kiss, CCR, Lynyrd Skynyrd, BB King. Something even tempo that can pick up and come back down. Freebird followed by Fortunate Son is a good example.
Anything without vocals so that it doesn't force me to actually think about it, just vibe.
Lately Chikoi The Maid (maidcore rock) or Gnome (just-riffs-rock?) to some dnb/techno stuff, depends on the mood and how hard I need to focus - faster is better then.
Honestly, I cant listen to anything while trying to concentrate. Music distracts me when I'm trying to focus on a mental task. Now if I'm doing physical labor or whatever, much easier. 80s music for sure. New Wave, synthpop. Good stuff.
Emancipator fucks heavy. I don't think I've ever heard an artist capture the feeling of misty forests and snow so perfectly. Just nature really. Safe in the Steep Cliffs and Dusk to Dawn are so evocative.
Hell yeah! I learned of them when my partner and I were walking around at a festival, and we passed a stage with the most relaxing music… we just immediately sat down, then laid down in the grass and vibed for a good half hour. Sooooo good.
I have the ADHD and unless it's a mindless task, I can't listen to music or it makes it much harder for me to concentrate. For anyone else with the disorder, I'd encourage you to at least give it a shot working WITHOUT music and see if it improves your concentration.