One of the very first of them, by the late '40s, was the "Charlivels" act. Valentino, Juanito and Charlie jr. (sons of the legendary clown Charlie Rivel), helped to open the way to variety acts in such places as Latin Quarter in New York, Ciro's at Hollywood and the very early Las Vegas lounges, without forgetting to grace european temples as Medrano, London's Talk of the Town, Copenhagen's Schumann, etc.
Here they are, in a tv show from the 60s (we posted the video in 2 parts).
But what they did in their act? Well, just everything.