Instead, I have what I call "loop songs", which are selected favourite tracks that span a range of genres from fairly heavy metal to Afrobeats. When I want to focus I pick a loop song and set it to repeat (the ideal volume varies per song, but is typically moderately loud). I can't explain how or why but it settles my brain far, far better than any white noise or "chill" playlist I've tried.
It's also a point of humour with my friends because they're horrified that I listen to the same song hundreds of times over a couple of days, while I'm perplexed that they can actually get tired of listening to a song to the point of disliking it.