Lloyd Price, who claimed to be "the true king of the fifties" is still alive. He will turn 86 in a few weeks.
While not exactly a rock, R&B or jump blues artist, Vera Lynn, who is definitely Old Guard, will turn 102 in a couple of months.
Lawdy, Miss Clawdy--Lloyd Price (1952)
Hollywood Square Dance--Vera Lynn & Anne Shelton (1949)
I had no idea that Vera Lynn was still alive.