You can skip the philosophizing and go straight to the list of songs I've written relating to the SCA, or go to the page with period music with tune and lyrics for prospective filkers. You can also check out some of my SCA stories.
The SCA and fandom have a lot of things in common, including many of their constituents (the family of Poul and Karen Anderson, for example). Naturally the SCA is one of the things people like to filk about. Given that the SCA is nominally about medieval recreation, there are arguments over just what is appropriate for an SCA filk.
Filking is a period practice (called contrafaction), so there's no question that the act of filking is an appropriate activity for the SCA. However, the vast majority of SCA filk is based on modern music. This is fine at non-events (for example, post revels or weekly meetings), but at an event, a filk to “Beat It” disrupts the attempt at a medieval atmosphere. In fact, the problem is far worse with songs than with, say, wearing tennis shoes to events, since the tune can be made at a far greater distance than the lyrics can be, so even if you're singing about the heavy list, people far away will hear “Beat It.” Of course, if you're inspired to write an SCA-related filk to modern music, go ahead; I've done it.
Thus one of our goals should be to promote filks of period music. There are several ways of doing this. One is to complain, loudly, whenever someone sings a filk to a non-period tune. Of course, that's rather rude, and more often than not it encourages deliberate inauthenticity. Finally, it does nothing to solve the fundamental problem: if people don't know filks to period tunes, they won't sing filks to period tunes.
The better solution is to encourage the proliferation of filks to period music. There are two bottlenecks:
You have to find music to write a filk to,
You have to get people to sing the filk
There is a large body of songs whose date is given as “traditional.” In most cases, this means “older than the person who compiled this songbook,” and most such songs cannot definitely be traced back to before 1700. You can probably get away with filks to traditional songs as long as you don't try to claim they are period; I've written some filks to traditional music, though I'm trying to minimize that in the future under the philosophy that it's just as easy to write filks to period music as it is to write filks to non-period music.
Of course, you have to find period music. It's possible: Greensleeves is perhaps the best known period song. (Scarborough Fair might be on that list, except the arrangement that's best known is post-period). The problem is that potential singers don't necessarily know the songs, and if your filk can only be sung by you, it's not going to proliferate. I've begun putting period music with tune and lyrics online to help address this issue.
There is also a well-known and extensive source of documentably period music: dance music. The Belle Qui pavane actually has lyrics (see Arbeau); others have had lyrics written for them (Dargason has two that I know of, and the Black Alman has one), and most English country dances may have started out this way. Dance music has a further advantage: a lot of people know the music, which means that a filk to dance music has a large group of potential singers. This is critical if you want the filk to proliferate: a filk based on Gathering Peascods will be sung far more widely and more often than one based on some medieval Latin plainsong.
For better or for worse, here are some of the filks I've written and/or I'm working on (in the latter case, the title is up but not the link). Inactive links are filks I've begun but haven't completed or don't like in their current form. The filks are listed in each category in they order they were begun (not necessarily completed).
This is the master list, organized chronologically. You can also search the master filk list.
Oh, and for those who care: You may perform these freely, as long as you credit me. You may make permanent recordings for non-profit purposes on the condition that 1) I get a copy, and 2) you credit me. If you do this, I'll include a link from the song to your site. If you want to make permanent recordings for profit, talk to me...
Songs to Period Music
Belle Quoi?!?
The Believers Bransle
What If I Never Weed?
The Summoner
The Madness of the Roman King
SCAdian Eyes
WARNING! Adult content: Around the World in Eighty Lays
Pasta in Good Company
The Quiche Lorraine Song
Columbus and Some Others
Writer's Complaint
The Battle of Courtrai
Songs to “Traditional Music” (possibly period)
Songs to Music I've Written
The Bravery of the Knight and Squire
Dance Filks (mnemonic songs for dancers)
Songs to Modern Music