As others have said, there is no Mozart effect per se. Studies have found that people who listen to classical music have enhanced memory, test performance, etc. but it’s not because the music made them smarter. It’s because it put them in a good mood and reduced stress, which facilitated those mental feats. The enhancements went away shortly.
Our daughter’s growing on a steady diet of punk rock, reggae, Sinatra and her mom’s top 40. She’s doing well.