...hmmm. I'd hate to see this thread take a turn along the lines of "old tunes = safe, comfy, boring", "new stuff = daring, exciting, fresh".
There's some truth to it, or else it wouldn't be a cliche. But it's too simple.
I gave a back-handed dis to Herbie way back in this thread. Hey, I've been listening to Herbie for nigh on 30 years. Listening to Herbie (or ____, fill in the blank) is a process, not an event.
What I didn't dig about HH at the Hancock / Shorter duet concert I saw was a lot of cliche "out" stuff. Like getting in there and yanking and plinking at the strings, a la prepared piano. Been there, done that. Why now, Herbie? Why here? The 20th century gave us a healthy respect for what we used to call "dissonance". OK, got it. Rule-breaking and boundary-pushing? We've done a lot of that. Next?
I'm simplifying, but I'm just trying to express the feeling I've got about it. If you immediately recognize it as a presentation of "something new", and the elements have more or less been around for DECADES, and there's no new vibe or feel to whole context, then how new is it?
To go back to the conversation analogy, there needs to be some germ of shared meaning in there, hopefully not buried too deep. For me, my liking usually correlates to there being some genetic trace of swing and/or blues (both terms used in the widest, most generic/generous terms possible) discernable in the sounds. Just my tendency, my personality.
Maybe I'm just getting old and curmudgeonly, or maybe I've just got a bellyful of the 20th century, but I do look for "gratuitous new-ness" when I'm frisking down new music.