Keith Richards is 71 years old. Yea, the old guy from the Rolling Stones. Mick Jagger is about the same age. Both still wear pleather and rock out on stage. Brian Willson from the Beach Boys is also 71, but he has toned down his performances quite a bit, but Mike Love still tries to recreate the Beach Boy glory days, despite not having a hit since 1988. Paul McCarthy has also classed up his appearance and is not jumping around like a thrasher, but then again he didn't do that in the 60's either. Ringo Star (or Dingo as he is sometimes deferred to thanks to Apple auto-correct), just creeps me out. Smokey Robinson has not changed in 50 years, were as Jerry Lee Lewis makes you want to go WTF.
I reference these performers because they are all over 70 and they all are still performing. But at what point does a performer need to either change their style so they don't need to put down their walker to smash a guitar on stage, or trade in the stage for a sound studio?