Entertainment / Literature / Filk: A specialized type of folk music or alternative music, often with narrative lyrics, that usually deals with science fiction or fantasy themes and characters. The subject-matter is often not original to the musician, but rather taken from literature, pulp fiction, movies, and pop culture. In some cases, the song retells a story written by a famous science fiction author or explores in greater detail a particular scene or character first created by that author. Because this subgenre often is an homage to another's published work, it is usually performed informally rather than mass-marketed, thus avoiding copyright infringements. An example might be a song about Gene Roddenberry's Star Trek Enterprise set to the tune of 'Jingle Bells,' or a song about H.G. Wells' War of the Worlds meant to be performed to the tune of Handel's 'Ode to Joy.' Other filk songs might involve completely original music, and they might deal with technological or fantastic themes more generally rather than paying homage to a particular science fiction story. Likewise, a single filk song might make allusions to several different works simultaneously. The only prerequisite convention of the genre is that it be appealing to the people who frequent science fiction conventions and enjoy such literature and movies.