The term “Mozart Effect” was coined to describe the alleged increase in brain development that occurs in children under age 3 when they listen to the music of Wolfgang Amadeus Mozart.
The idea of a “Mozart Effect” grew from one study in 1993 at the University of California, Irvine. Frances Rauscher, a former concert cellist and researcher on cognitive development, and physicist Gordon Shaw studied the effects on a small number of college students. After the students listened to the first 10 minutes of a Mozart sonata, the researchers found a temporary improvement in spatial-temporal reasoning on the Stanford-Binet IQ test. A few years ago, another study conducted on college students found that those who listened to a Mozart sonata performed slightly better on a brief spatial reasoning task. The effect was measured immediately after listening to the music but no long-term effects were studied. Attempts to replicate this study produced very inconsistent results. No studies have been done on infants or young children that show cognitive gains attributable to listening to classical music. Though it was widely reported in the media that Mozart may make children smarter, the most that could be claimed is that listening to Mozart enhances short-term IQ in college students as measured by IQ tests. The "Mozart Effect" has taken on a life of its own in the media and spawned numerous books, CDs and software. Several questionable studies have been generated to promote the “Mozart Effect” industry.
While the "Mozart Effect" is questionable and there is no real evidence of the direct impact on IQ or brain development, music education does have positive side effects in academic efforts – discipline; understanding of systems, structures, and the use of symbols; and understanding the world in a fuller and richer sense.
If you wish to dive into both sides of the issue, visit: http://skepdic.com/mozart.html