From a study by M. Keyhani and M. Shariatpanahi:
Materials and methods: Forty medical students randomly assigned to music and control groups. This randomization was performed in a way to maintain an equal sexual distribution between the two groups to lower probable bias. Fifteen minutes of classical music (Piano sonata K576 by Mozart) played for volunteers in music group, while in control group 15 minutes of rest allowed before performing tests. Wechsler memory scale and reverse digit count test were performed by both groups. The results were compared between two groups and analyzed by statistical methods.
Results: Corrected WMS score in music group was 113.97 so it was higher than control group [emphasis added] witch [sic] was 107.22 (p<0.01). Resulted memory quotient (MQ) in music group was 131.75 and it was higher than control group [emphasis added] which was 116.6 (p<0.01). Performing time of reverse digit count test (from 100 to 1 by interval of 7) in music group was 41.50 sec and it was lower than 51.0 sec of control group but it was not statistically significant (p>0.05). Reverse digit count test errors in music group was 0.45 and was lower than 1.20 of control group [emphasis added] and it was statistically significant (p<0.05).
Conclusion: Music listening improved attention and memory performance [emphasis added] in music group comparing to control group.
Here we see that listening to only fifteen minutes of a Mozart piano sonata was able to improve certain kinds of test scores in already well-educated adults. When we consider all the other research into memory, testing, and brain function that has been done on classical music, there is no conclusion other than: classical music works!
http://www.youtube.com/watch?v=jd4qke8Bd0g
Change the station on your radio, or if there is no classical station nearby, invest a few dollars in a CD, or listen online.