About Filk Music
"I Know It When I See It"
Filk music is a fuzzy medium. Much of it you will only hear late at night at SF conventions (and if I said "just as well", all manner of filkers would rise up in righteous wrath and strangle me with their guitar strings, so I won't). Yet some of filk's most prominent, best-loved performers are professionals who make their livings singing in bars and at weddings and recording CDs -- and using the same material in all those venues. Much of the Doctor Demento playlist and most of Weird Al Yankovic's material arguably qualifies as filk (though there are sharp disagreements about this among filkers) -- but folk and folk-rock bands such as Golden Bough and Tempest have also wandered under the filk umbrella, and you will find filk songs set to tunes by the Beach Boys, the Beatles, and Pink Floyd.
It is not a coincidence that "filk" is a derivation of "folk". I won't try here to pin down the moment when filk was born, but it seems to have become a significant subset of SF fandom either during or just after the "folk revival" of the late 1950s and early '60s, in the heyday of the Weavers and the Kingston Trio, of Peter, Paul & Mary and Tom Paxton. Filk circles at cons have a good deal in common with the "hootenannies" and college-campus coffeehouses of that time and place, and writers of filk lyrics (myself included) have borrowed tunes from many songs written or popularized in those years.
Though there's a wide range of material nowadays, filk songs can be broadly grouped into roughly two categories: parody/humor and alternate-folk. The parodies are largely self-explanatory, consisting of songs zinging popular media universes (Star Trek, Harry Potter, etc.) or literary characters, or merely taking social or political potshots in the Tom Lehrer/Weird Al vein. "Alternate folk" is that material which is essentially serious and drawn from general themes or specific works in the SF/fantasy genre. But not all filk fits these parameters. With the advent of relatively inexpensive music-production technology, there's a growing "filk rock" segment coming into prominence, and you can find filk songs and albums for sale from Amazon, iTunes, and CDBaby.
About convention filk circles: enthusiasm, not musical skill, is the chief prerequisite for attending and participating. Veteran musicians sit side by side with pure amateurs, and each has more or less the same chance to perform. Sing-alongs are a frequent feature, and the songs presented may be brand-new originals or familiar standards. (Just don't ask for "Banned from Argo" when your turn comes around. Trust me on this one.)
The best way to explain filk, though, is by example. The links below connect to an assortment of the 'Net's filk resources. The list is far from exhaustive, but it should get you started. Or you can click on the button above to look at some of my own lyrics.