Mozart has been said to aid studying and learning. It appears that it may "temporaily" raise the IQ.
Be wary of relying on it though. Bit hard to sit through an exam without classical music if you do it everytime you're studying.
One of the resons that some folks are able to do their homework with ease while listening to loud music but not transfer this to the classroom is probably because the music they were listening to became an anchor and it's missing in the classroom.
Alex