@Felthry And I know you don't care for music with singing, but it is inherently a singing-oriented performance art. Some folks will even just write out the lyrics to a filk, trusting someone else can perform it.
A friend of mine wrote a filk based on Jefferson Airplane's song 'White Rabbit' about some times that we had to bathe our pet bunny, 'Wet Rabbit'. Didn't perform, though she could have, and left the text where anyone could pick up their instrument and sing it.
@Felthry It's a (mostly) science fiction fandom bit of performance art! Songs that usually take the tune of something familiar and rewrite them to be about some fandom thing.
It's like when Weird Al Yankovich did a song about Star Wars to the tune of 'American Pie' (although since Weird Al's a professional that's not got the amateur-work connotation of filking).