According to my marja' (Sayyed Fadlallah), it's okay to listen to certain types of music as long as the requirements of it being halal are met (E.g. it's not party music, or as another example it helps you focus more).
Personally, I listen to alot of study music mainly due to the fact I can't focus at all while studying, even if there isn't any background noise. Listening to it has considerably improved my focus anywhere I go, even during class.
For anyone that's confused:
Hope this helps.