Filk music is both a musical culture, genre, and community tied to science fiction/fantasy fandom and a type of fan labor. The genre has been active since the early 1950s and played primarily since the mid-1970s. The term (originally a typographical error) predates 1955.
The word "filk" has also evolved as a verb, with two common meanings:
1. To participate in a filk song circle, as in, "We were filking last night until three in the morning." 2. To write a filk music parody of an existing song, as in, "I filked 'Hope Eyrie'." When used in this way, "filk" does not imply that all song parodies are considered filk music, nor does it imply that all filk songs are parodies. Setting satirical or parody lyrics to established tunes is not exclusively the province of science fiction fandom. Works of parody music such as those found in MAD Magazine or performed by Weird Al Yankovic have their own long-established traditions and history.