How can musicians remain relavent?

Hi all,
Wanted to get your opinions on this. A bunch of people and I were talking about a particular unnamed band the other day, and the opinion was split as to whether the band was still "good" anymore. I personally didn't think so, but it got me to thinking about something that I thought I woudl run past you good folks. Some bands were so extremely popular during their "day" that their legacy lives on. That legacy is rooted in the past, and is definitely important in and of itself, but there are bands that are so good that they have made a legacy for themselve by virtue of the music they have made in the past, AND in the present. I personally think that a band stays relavent to multiple generations if it can find a way to re-invent itself yet still maintain it's original sound. Does that make sense? What do you all think?

-P

1. Music is big business.

2. Artisitic integrity is not a commercial objective.

3. Taste is entirely subjective.

4. What is relevant to one, is tasteless meaningless crud to another, irrespective of what generation he or the band might be in.

5. If legacy is record sales, then measure promotional budgets past and present to get your prediction, not perceived social relevance.