Classical music
During the 1990s, several research papers and popular books wrote on what came to be called the "Mozart effect": an observed temporary, small elevation of scores on certain tests as a result of listening to Mozart's works. The approach has been popularized in a book by Don Campbell, and is based on an experiment published in Nature suggesting that listening to Mozart temporarily boosted students' IQ by 8 to 9 points. This popularized version of the theory was expressed succinctly by the New York Times music columnist Alex Ross: "researchers... have determined that listening to Mozart actually makes you smarter." Promoters marketed CDs claimed to induce the effect. Florida passed a law requiring toddlers in state-run schools to listen to classical music every day, and in 1998 the governor of Georgia budgeted $105,000 per year to provide every child born in Georgia with a tape or CD of classical music. One of the co-authors of the original studies of the Mozart effect commented "I don't think it can hurt. I'm all for exposing children to wonderful cultural experiences. But I do think the money could be better spent on music education programs."

Q: Where was the experiment originally published?
Nature