50 years from now, people will still be playing The Beatles, Stones, Who, Led Zep, while nobody will even know anything about these bands today.
The music of your youth sticks with you I think. Those older bands get incorporated into the youth of today, but they take on new bands as well.
As much as I hate Kings of Leon’s new album (their first two were excellent) it is hard to imagine people not wanting to listen to those songs and taking them back to some excellent times they had listening to it.