work up to it, play some of the great metal for kids stuff out there. trust me there is some. My sister (4 but as smart as a 6 year old... I'm serious right now we're working teaching her how to read time since she already can read and write a little, oh and she can do three quarter profiles in art.) anyways My Sister hasn't really listened to any metal, but one her favorite things to listen to is my Ramones Mania CD with 25 songs by The Ramones, And then she loves my Electronica. you can probably find theres a CD out there of Metal Bands covering Childrens Songs.