I thought of this as a topic for last week, and then got side-tracked into something else. Here’s the text:
If you know the song and the words, it is possible to follow the original version. Here it is in modern notation:
If you are singing it as a round, the entries come in at the point marked with a +. The last two lines are the ostinato parts. You can see that it is just a two phrases, which can be sung as a little round themselves. In the lyrics, the weird letter that looks like a combination of b and p stuck together is for a “th” sound.
If I do this in class, I tend to choose a lower key. D major makes it easy to have a drone played on whatever string instruments (violin, cello, guitar) are around, or they can play all or part of the ostinato. You might have some nifty recorder players involved as well.
I’ve got these pictures from the Wikipedia entry http://en.wikipedia.org/wiki/Sumer_Is_Icumen_In where you can read the source, history, modern English translations, alternative versions, parodies and other delights associated with the song. Well worth a read.