If you're studying, I would recommend non-vocal music. Recent research shows that even when the vocals are in a foreign language, they distract from your reading. As I write for a living, and on deadline, I'm familiar with listening to music while I concentrate on the task.
I'm assuming you're open to classical.
That said, I'd look for composers who are more upbeat. Much of the time this takes us back further as one ingredient in modern music is its tendency to be downbeat. Shotakovich comes to mind. I love his stuff, but not when I need motivation.
Debussy is pretty good at aiding concentration and most of his work is optimistic.
John Ireland's music might be obscure but it is nice to concentrate with.
Moving back in time, Beethoven is dramatic and certainly conveys a can-do spirit. Even though there are lyrics in his 9th, it is otherwise perfect, but so are the 4th, 5th and 6th symphonies and they are vocal-less.
Haydn is very upbeat and tuneful. Vivaldi works as well.
Lots of people like Bach for its energy, too.
Hope this helps.