Earlier it has been thought that listening to classical music, particularly Mozart, enhances performance on cognitive tests. However, recent findings18 show that listening to any music that is personally enjoyable has positive effects on cognition.
18. Schellenberg EG, Hallam S. Music listening and cognitive abilities in 10- and 11-year-olds: the blur effect. Ann N Y Acad Sci. 2005 Dec;1060:202-9. PubMed