Filk is the folk music of fandom. Mostly it simply means that fans who like to sing make new, science fiction and/or fantasy related lyrics to popular songs and perform those in fandom meetings. (See more in http://www.filking.net/filkfaq/what-is-filk/.) Spektre fandom includes a group called The FilkFreaks, originally from the Smial Morel (a local smial of the Finnish Tolkien Society). Most of the filks here are FilkFreak productions, performed in various meetings of the Finnish fandom.
Finncon 2006 kunniavierasfilkit
Finncon 2007 kunniavierasfilkit
Finncon 2008 kunniavierasfilkit