We hit this area of theory in my class last Wednesday. It was pretty awesome for me because polyrhythms are something I enjoy in music, particularly in classical music and prog rock, but I never understood how to count them.
2 against 3
[VIDEO]http://www.youtube.com/watch?v=8ePgZPuhCAo]Polyrhythms: 2 against 3 and 3 against 2 - YouTube[/VIDEO]
3 against 4
[VIDEO]http://www.youtube.com/watch?v=wQWQUc8CCa0]Polyrhythms: 3 against 4 and 4 against 3 - YouTube[/VIDEO]
4 against 5
[VIDEO]http://www.youtube.com/watch?v=u6P2w7dJ3Mc]Polyrytmik 4 mod 5 og 5 mod 4 - YouTube[/VIDEO]
This guy has a ton more videos, but these are the most basic ones to learn. I hope you all enjoy this!
Thanks for posting!