What's a good learning/study music album you would recommend?

Here's a tip I picked up somewhere. Make a playlist. An hour or two worth of music. ONLY listen to it when you're studying. I've found my brain just blocks it out after a few times through, but it triggers my subconscious or something. As in, if I'm not feeling like studying, I put it on and my brain just goes,"OK, it's time to study." I change it up when I'm starting a new long task (writting a new book, starting a new semester, whatever). At first, I find myself listening to it, but it doesn't take much repetition for it to fade into the background.