Do we stop caring about popular music in our 30s?

Not me - I'm 51.

In some ways I've very picky about my music, but in other ways I have very wide-ranging tastes.

I listen to http://www.radioparadise.com/ with a text file open, then write down the artists I like, and their albums. That is, I don't buy just one track, I always buy a complete CD, as I commonly find that I like tracks that don't get airplay.