This is not an SCA approved page, for official SCA information go to www.sca.org.
SCA stands for the Society for Creative Anachronism and is very basically a group of people who get together to better learn about and experience the middle ages by recreating a period environment.  SCA events are always participatory, you can't come and watch.  You get to play the game with us.  To participate you don't have to be hardcore - you can just borrow some garb, walk around, meet people and learn about the past.  That's about as simple as I can make it.  In the SCA people approach every possible aspect of historical lives and try to recreate it, from shoes, to food, to cosmetics...and of course, music.