The biggest difference in whether or not music has a negative effect on concentration is whether or not the music has lyrics. Human voices are very distracting, even if the voices are in a language you don't understand (or a fake language)! In cognitive psychology, this phenomenon is known as the Irrelevant Speech Effect. With human voices playing, people can hold significantly less information in their head at once. This makes paying attention difficult. If you want to listen to music while studying, you should make sure it doesn't have any lyrics.

You also may have heard that listening to classical music can make you smarter. Scientists refer to this finding as the Mozart Effect. In the original study, participants who listened to Mozart, a famous classical composer, performed better on a subsequent test of spatial-temporal abilities. Further studies, however, show that it's not Mozart specifically that improves performance, but simply doing something that puts you in a good mood. If you don't like classical music and it puts you in a bad mood, then your performance will not be enhanced. Listening to any kind of music that puts you in a good mood (or even reading a short story) can improve your performance on some types of tests.

Reference: Colle, H. A., Welsh, A. (1976). Acoustic masking in primary memory, Journal of Verbal Learning and Verbal Behavior, 15(1), 17-31. And the feature model Nantais, K. M., Schellenberg, E. G. (1999). The Mozart effect: an artifact of preference. Psychological Science, 10(4), 370-373.