CabeCoff posted a thread named "The Music Man" with the summary "This idea is original, and I have not found a SCP that resembles it. For more details, please join me."
Backstory: The entity says his name is Harold Hill, who was a traveling salesman. He reportedly disappeared after leaving an Idaho town, after starting a band with the school students there. Subject asks occainsionaly about an individual named Marilyn, who, after searching several databases, was a woman who lived in Idaho as a piano teacher. He was found after an incident where his effect was activated outside a concert in Indiana.
As user Montala points out, this is an exact description of the plot of the stage musical and film The Music Man, but CabeCoff presented it as "original".