Nat King Cole was the first black entertainer to have a prime time show. His show was a big hit. His audience was primarily white. Nat King Cole had the best talent on his show. He had a lot of friends in Hollywood. People like Frank Sinatra, Bing Crosby, Dean Martin etc all came on his show. Bill Cosby is nothing compared to Nat King Cole.
IIRC it was all singing. And yes the greats went on the show. We also watched Durante, Como, Dinah Shore, the Grand Ole Opery, Les Paul and Mary Ford, Tennessee Ernie Ford and whatever else was on.
I think Dinah and Les Paul each did 15 minutes and they split a half hour.
One of the best piano players there ever was, but most only know him as a singer.