For those of us over 60..

55 next week,, gotta go with The Stones, capped at Some Girls.  Lucky enough to see them once. Tie for 2nd with The Grateful Dead (100+) and The Clash (1).  Wait, 3 way tie, Bob Marley & the Wailers (0), that way I get Peter Tosh (1) to boot..  I know the question was for one, but I'm just a punk kid of 55, I can bend the rules............(I just got home from The Jesus Lizard's possibly last show ever and they gave a class for the kids today on how to do it, whatta great time.)

Moody Blues, Jethro Tull, Uriah Heep, Pink Floyd, Emerson Lake and Palmer, Crosby Stills Nash and Neil Young solo, Cat Stevens, Al Stewart, Gilbert o Sullivan, Christopher Cross and the great thing is with my Hi Fi setup now in my dedicated sound I still listen to them only now I fully realise just how good they were

Bachman Turner Overdrive -  gimme your money please?

Now, in my mid to late 60s, the one band (artist) that best describes my life, at least at this point, is John Lennon - "Imagine". I'm pretty much tired of religion and politics.

For musical enjoyment, I find myself falling back on my old 60s - 80s favorites: Van Morrison, Leonard Cohen, Bob Dylon, Neil Diamond, Jennifer Warnes, Neil Young, Pink Floyed, Fleetwood Mack, Moody Blues, Red Rider, Lover Boy and anything Classic Country. From time to time I still enjoy the Classics - Vivaldi, Bach and Beethoven.
Modern artists that would most define my listening pleasures of today: Amos Lee, Chris Iisaak, Ray La Montagne, Jack Johnson and anything with real instruments - Amy Winehouse, Hugh Masekela, Nora Jones, Jane Monheit, Chris Botti and anything Celtic, Jazz, Folk or Bluegrass...Jim

To the OP’s intended point, my answer is one word:

ZAPPA