According to this news article, it seems that if you want your child become a good musician, you could start the lessons before he gets spoiled by any high frequencies.. "Now, scientists at the University of Florida have added a piece to the puzzle. In a series of unique experiments on a pregnant ewe designed to record exactly what sounds reach the fetal ear, UF research has bolstered previous findings suggesting that human fetuses likely hear mostly low-frequency rather than high-frequency sounds." So what would we start with then? Disco Inferno, perhaps? Some Jamerson? Best of Rocco's lines?