What do Houdini, Bob Hope, and Don the Talking Dog have in common? They all started out in vaudeville. What was vaudeville? The word is French for a kind of comic song, but in North America it came to mean theatrical presentations of unrelated acts—singers, comics, dancers, magicians—and it dominated our popular culture for half a century, roughly 1880–1930. Today, with every kind of music and show available instantly at the touch of a button, it’s easy to forget that for all of human history, until about 1900, all entertainment was live. In the Middle Ages, for example, people found good music in church or went to a beer hall to hear a wandering minstrel. By the 19th century, owning a piano was both a status symbol and a way to make your own kind of music at home, with family and friends. A “musical evening” might feature a daughter …