When I was in community college and taking a course for math study strategies for students with disabilities (test anxiety and ADHD in my case), the professor recommended that we listen to music while we study.
There were some catches to what was recommended. Lyrics were not encouraged, because they were distracting. Fast music was not recommended because it would get you excited. The idea was to listen to something kind of neutral that was still enjoyable.
I love movie soundtracks for studying music, generally music by Alan Silvestri (Avengers, Captain America, Back to the Future), Hans Zimmer (Pirates of the Caribbean: Dead Man’s Chest, Lion King, Prince of Egypt), or John Williams (Harry Potter, Star Wars).
I also enjoy Lo-Fi mixes. There are original Lo-Fi pieces, but I admittedly prefer remixes, withLegend of Zelda and Pokemon music remixes being my favorite. There’s just something about the beats that make it easier for me to focus.
I have also found that a song with lyrics can end up being all right for study music if it is one that you’re extremely familiar with, and therefore won’t get distracted by the lyrics.
My main recommendation would be, whatever you’re listening to, make sure it’s not too loud. It’s not fair to the people around you if they can’t focus because your music is so loud that they can hear it and it’s distracting (and it’s annoying)! It’s also just not good for you either. If you take out your earbuds and you can still hear the music, it’s too loud. Especially if you’re in a library, try to be mindful and to keep it down. I have lost count of how many times someone has sat down near me with music so loud that the next desk over is shooting angry looks at the person.
So find what works for you, be considerate, take care of your hearing, and good luck!