the Mother of all Polyrhythms
Three against two, the original polyrhythm, is best conceived in six, because six is divisible by both two and three. Listen to the high conga part playing the cycle of three. The low conga is playing a cycle of two, and they meet at the beginning, on the downbeat of one. The shaker, in the background, is playing on all six counts. These exercises are designed for beginners, to help you become more familiar with polyrhythms.
Three against two-MOM.MID
Play the top line (the "red" part, if you have Netscape3.0 or newer) with your strong hand, and the bottom part (the "green part") with your other hand. Notice where the hands fall both together. If you're right handed, the pattern is:
Both, right, left, right.
Focus on your strong hand for a minute, counting "1,2,3" along with the rhythm. Then shift your focus to the other hand, the one playing the "green" part. Count "1,2,1,2," along with the green part. As your mental focus changes from three to two, the rhythm will feel different to you.
After you've played the rhythm along with the MIDI sequence on your computer, try it without it. Put each hand on a different sound source, say, your leg and the table. After playing awhile, switch hands. The hand that was playing on your leg is now on the table, and vice versa. The reversal of the sounds will give you a different perspective on the rhythm. This works well on any two sound sources, for example two bells of different pitch, or the rim and head of a tom tom or djun djun.
Play this rhythm until it is completely natural. Meditate on it. It is much deeper than first meets the ear.