How about introducing them, for example, my favorite band called Nightwish (most likely many of them already know the band,I'm quite sure)? If you are not familiar with the band, here's some examples from their first, second and newest singer:
Era of Tarja Turunen (1996-2005):
Era of Anette Olzen (2007-2012):
The master piece of Tuomas Holopainen (the creator of Nightwish, no, he IS Nightwish) IMO
Oh god. No Miley Cirus or Justin Bieber, please!!! Give them something good! Something that will stimulate them instead of numb their brains with horrible, horrible disney-machine-made child celebrities. Maybe some New Wave? New Order is spectacular. The Cranberries, also, are great for teenage girls, I don't care what era you were born in. The Cure, too. Totally respect your classical music decision. Hip-hop, too, I think lots of kids love that stuff. Maybe some TLC- Waterfalls.. Something that sends a good message. Kids these days listen to the radio, which is full of crap, crap music. Gosh, Deerhoof is fun. Bjork... I'm trying to think of bands with female singers. A.P.P.L.E. lol. Credence Clearwater Revival (not female singer, but very very good)... Neil Young... Johnny Cash (the clean stuff)... Get a good spread going. Influence them, you know? Don't submit them to bad radio just because it's "popular".
Hip-hop would be good. I'm not knowledgeable enough about it to recommend anything besides TLC and Coolio's Gangsta's Paradise. Snoop Doggy Dogg?