[bsder]

Do the young really care about the back catalog anymore?

I'm not just being snide. Think about Elvis. When was the last time you heard something from Elvis on the radio or in your stream?

[throwawayjava]

It's definitely a sliding window. Elvis is not so important but stuff from the 1970's to the 2000's remains popular with kids.

Heuristic: parents pass on their teenage music preferences to kids but don't pass on their own parent's teenage music preferences to their kids?