Abbott and Costello! William "Bud" Abbott and Louis "Lou” Costello, American comedy duo whose work in vaudeville and on stage, radio, film and television made them the most popular comedy team during the 1940s and early 1950s. Their verbal bantering routine "Who's On First?" is considered one of the greatest comedy acts of all time. Here is a vintage movie still photo by both stars in a spectacular "Who's On First" display where even the names on the baseball field are the ones used in this great film, i.e. first base is "who's on first", second base is "what's on second", third base is "I don't know", short stop is "I don't care”. A classic from the Golden Age of comedy.