I grew up on music pretty much the polar opposite of metal: my dad was a military man with Victorian sensibilities, so we listened to an awful lot of military marching band music and waltzes. I AM NOT KIDDING. Also, classic movie soundtracks, like Chariots of Fire. We also listened to a lot of Nana Mouskouri and Mireille Mathieu. Again, I am not kidding! My parents also adored Roger Whittaker and The Irish Rovers. Actually, I can credit the Irish Rovers for interesting me in Celtic music, Irish culture, and folk music in general, and I still have a really soft spot for Roger Whittaker.
I don't think I ever heard any metal until I was about 12 or 13 (which would have been about 1986), the height of hair metal/glam metal. I can't list all the bands from that era that I listened to, but I can tell you the one that amused my parents no end: Twisted Sister. They thought these guys were hilarious! We had this show in Canada back then that came on the CBC at 5pm every week night called Video Hits. They used to play this video every so often and it always got my parents' attention and we all had a family laugh!