Most of those old acts were pretty dreadful. Almost all of those old timers had lost their voices. At one point, Roy Clark came out to do about 15 minutes (they rotate shows at the Opry, and they run 15-30 minutes). He was absolutely superb. He still sounded great, and he even did "Thank God & Greyhound".
STYX was rolling thru with their old age tour a year or so (Probly more) back and my daughter wanted to get me tickets because I listen to their original analog 12” vinyl lps, a.k.a. - records quite often in the mix.
She understood when I declined and told her that I had recently watched a Quello concert of their latest concert and I would really rather preferred to remember them as the kick-ass rockers of my youth.
Roy Clark always looked like he was enjoying playing tons more than everyone else in the room listening.