I'm old enough to have been a fan of Buffy, but didn't watch TV back then. I also enjoy some modern pop music but, in the vast majority of cases, have never seen the artists. I'm also terminally bad at faces even if I have seen them (I've had to ask my wife whether a picture of her was her; she took it well).

I did actually recognize Alyson Hanigan, since she has a few distinctive expressions and features, but had no idea of the rest.

All that said to say: thanks for the explanation; me not getting the joke or reference doesn't mean it was a bad one.