I'm like you, when I'm reading/studying I can't have anything with lyrics in it or I'll insert the words into what I'm reading, which will get stored into my short-term memory.
I tried classical but it didn't really do what I needed it to. Tried jazz to the same problem, there wasn't a BEAT there that I could tune into to tune out the outside world.
Most techo/house/D&B/fucking raver synthetic crap had words in it or just plain sucked.
I was turned onto
Sound Tribe Sector 9 and loaded it into pandora. I really liked the sound; kinda funk, kinda techno, kinda jazz but hardly anything with lyrics. Pandora was also pushing out songs from all instrumental bands which led me to hardly skip any artists. I listen to them now when studying for computer shit.