If you read music or care anything about music history, you might open this page to read along with the music for the video below.
http://en.wikipedia.org/wiki/Pachelbel's_Canon There are two sound files on that page too—one of a piano arrangement and one on synthesizers. That would give you a taste of the range of its existence.
Then there's this, a home video of someone adding electric guitar. Some of you have probably seen it already, as it's been viewed over 66,000,000 times. Still, I found it today, as a link on the Medieval Trivia list. The original is baroque, not medieval, but it's a nice treatment and I'm glad someone sent it to that list.