What music actually helps you focus without becoming background blur?

I've tried a lot of different music for focus and I keep running into the same problem — after about 20 minutes it just fades into the background and I'm back to procrastinating.

Brown noise works sometimes. Lo-fi sometimes. But I feel like there's a sweet spot I haven't found yet.

What's actually working for you? I'm curious about specific types of music, not just 'classical' or 'lo-fi' — I want to know the texture of it.