We’ve all heard about the “Mozart Effect” -- the concept that listening to classical music at an early age helps make children smarter. Similarly, it has long been held that learning a musical instrument also helps develop the brain differently, and can improve math ability specifically.

French Researcher Dr. Alfred A. Tomatis first invented the phrase “Mozart Effect” in 1991. His book, Pourquoi Mozart?, was based on thirty years of work with learning disabled children and explored the broad applicability of Mozart. He claimed to have helped adults fight depression, learn foreign languages faster, develop better communication skills, and improve both creativity and on-the-job performance. Some musicians, singers and actors also claim to have found it helpful in fine-tuning their artistic skills. Tomatis wrote 14 books, and numerous articles. Only a few have been translated into English.
  Symphony No.40
  In G Minor, K.550

  Piano Concerto In   C No. 21, K.467

  Piano Concerto in   C No. 24, K.491

  Violin Concerto in   D No. 4, K.218

  More Mozart

In the United States the notion was first written about in a 1993 paper by Frances Rauscher and Gordon Shaw. It reported that brief exposure(8-10min) to a Mozart piano sonata produces a temporary increase in spatial reasoning scores, amounting to the equivalent of 8–9 IQ points. Over the next several years the research paper was mentioned in several newspapers including the New York Times and Boston Globe.

In 1998 Zell Miller, governor of Georgia, announced that his proposed state budget would include $105,000 a year to provide every child born in Georgia with a tape or CD of classical music. Clearly he believed in the Mozart Effect and it’s connection with music and mental ability. There has been numerous studies to approve and disapprove this theory but in the end a person has to be their own judge.

Chip Heath, an associate professor of organizational behavior,  and Bangerter compared different. U.S. states' levels of media interest in the Mozart Effect with each state's educational problems. They found that in states with the most problematic educational systems (such as Georgia and Florida), newspapers gave the most coverage to the Mozart Effect. In fact spikes in media interest generally correspondes to events outside of science.
Reference : Stanford University : article

The Mozart Effect became popular through Don Campbell’s book, ”The Mozart Effect” in 1997. The basic theory is that listening to Mozart’s music will temporarily increase your brain’s ability to generate and conceptualize solutions to multi-step problems. Benefits to Heal the Body, Strengthen the Mind, and Unlock the Creative Spirit is also referred to in his book. Although controversy surrounds this theory there is considerable evidence that supports a relationship of sound and music to increasing human learning and abilities.

Swiss psychologist Adrian Bangerter, found that the Mozart Effect received the most newspaper mentions in those U.S. states with the weakest educational systems—giving tentative support to the previously untested notion that rumors and legends grow in response to public anxiety. Concern about education was so great, in fact, that several U.S. states actually passed laws requiring state-subsidized childcare centers to play classical music or giving all new mothers a classical music CD in the hospital.