That's Stan Kann on the left in the photo at left. With him is Johnny Carson and this was probably taken at The Tonight Show on one of 77 nights when Stan Kann was a guest.
Mr. Kann was a ubiquitous talk show guest for years, appearing with Mike Douglas, Merv Griffin and others. He was a concert organist and TV host who had a unique collection of old inventions and gadgets, many of them vacuum cleaners. For a time, he performed at the Fox Theater in St. Louis and appeared on a local TV show hosted by Charlotte Peters, the mother of cartoonist Mike Peters.
Kann moved to Los Angeles in 1975 but flew all over the country to make appearances. When Johnny Carson or some other host needed someone to fill a spot, they'd often call on Stan to show up with an array of his gizmos, most of which did not work when he attempted to demonstrate them. Kann was frenetic and filled with energy and often clumsy as he tried to get his exhibits operating, and audiences often found it very funny. Johnny Carson would act annoyed but he knew it was good television and would always invite Stan and his silly machines back again and again.
As this obit tells us, Stan Kann died recently at the age of 83. A memorial service at the Fox Theater is planned and I think it would be a lovely tribute to his act if the curtains refused to open and the microphone didn't work.