Sunday again!? Better have a laugh, then

This came in from Prospero's 'old' friend Veronica with the advice: 'For over 55s'. But everyone's entitled to have a good musical laugh with Frank Sinatra, Sammy Davis Jr, Dean Martin and ... who's the other guy*? (Thanks, Veronica, wach this space for either a new section or even a whole new site that might just be called 'Wrecked Wrinklies Wrap' - WWW, get it? - to which you will get a free subscription.) (*Answer below!)>
It's Johnny Carson, longtime host of The Tonight Show on NBC, which used to be presented to a live audience in a theatre, before moving to a studio in the mid 1960s, and now the subject of much dispute between Jay Leno and David Letterman - hey, we're up to date here, you know.