I don't know any singer who went on tour in his very late 70s or at 80 or more.
Ian Hunter is 79 years old, is still touring rock clubs, and is in the midst of a series of reunion concerts with two other members of Mott the Hoople.
Ringo Starr will be 78 in a few days and still playing gigs where he drums and sings lead.
I just saw John Sebastian (Lovin' Spoonful), age 74, play a solo gig.
Just some examples.