An illustrated song is a type of performance art that combines either live or recorded music with projected images.
Nickelodeons were arcade style machines that worked by hand cranking a mechanical handle which turned an internal mechanism which played an audio recording, and had a visor like viewing window, displaying accompany still images projected from glass slides, and also flip cards.
So called nickelodeons, because a nickel was required to engage the cranking mechanism, in order for the viewer to start the show.
[1] Several film stars began their careers as models who illustrated lyrics through a series of song slides.
These stars included Roscoe Arbuckle, Fanny Brice, Eddie Cantor, George Jessel, Alice Joyce, Florence Lawrence, and Norma Talmadge.