"Shoegaze" or "space rock" are the two genres that really, help me focus too, and for the same reason. They're usually my go-to if I'm working from home and trying to concentrate. If I have bad food coma _and_ I need to concentrate, I will usually switch to techno (without words). What I've found is that I can't listen to anything with lyrics if I'm also trying to concentrate. Any words, even if I"ve heard the same 29374902374 times. completely pulls me into the song - I can't multitask like that!