I'm just tuned in too much to the sound of the electric guitar... Particularly lead guitar.
There's stuff I kike that has no guitar whatsoever but it's made up for in other ways.
If playing live is relevant (and who knows - maybe it no longer is), but if playing live is relevant, then the audience will tell me if what I'm doing is relevant. Do I try to be relevant? Well I write for me, and if it works for the audience, then at least for that audience, I was relevant and I'm good with that. I don't write to please the audience, but it's nice when it happens. But I won't persist in inflicting the same thing on an unresponsive audience. So that's the measure of relevance, for me.
As for the older music...
I did not grow up listening to music. I have no desire to revisit some era to resurrect the soundtrack of someone else's life.
I open up iTunes and listen to the new stuff on Tuesday's. I remember jumping through hoops to find certain music just a few short years ago. Rarely do I want something that's not on iTunes now so I don't feel like I am missing out at all.
If a classical musician plays something from the 1700's, say a nice Mozart piece, would he irrelevant?
If music is good and you like it, I say play it!