Filk

Filk is a subgenre of folk music that originated within science fiction and fantasy fandom, where the lyrics revolve around subjects of interest to the fandom community—science fiction and fantasy, but also pop culture, technology, and any other topic that captures the singer's interest.

Filk is usually performed at science fiction conventions, sometimes through stage performances, but more commonly in filk circles, where participants share songs at late-night sing-alongs.