Studying to music all depends on what you're listening to of course....
It won't be very productive if you've got Cannibal Corpse blaring from the cd player for example, but generally soothing music at a slow tempo will aid you. Bach is perfect of course, as is ambient/electronic music. I'll recommend some more music:
Underworld- Push downstairs
Enigma-Sadeness
Praise-Only You
Deep Forest-Deep Forest
Bach- Augnute Ruh and Goldberg Variations
Satie- Gymnopedie 1, 2 and 3
Chopin-Nocturne in F minor
Beethoven- Symphony in F major(Pleasant thoughts upon arriving in the countryside)
Most of the other impressionist's work(eg Debussy) is perfect as they almost always reflect quiet, contemplative moods.