QUOTE(frumpybabes @ Jun 10 2006, 07:22 PM)

There are two types of roll, single stroke which is one of each stick and double stoke which is two of each stick.
Actually, there are 3 types, you forgot buzz roll.
Single stroke: does what it says on the tin. Metronome practice, practice on a pillow to make sure you're getting the correct action.
Double stroke: RRLLRRLLRRLL etc. You only hit the first of each pair, the 2nd stroke is a rebounce. The main trick is picking the stick up after the 2nd bounce, and getting the 2 bounces close enough together. You also need a smooth change from one hand to the other, and a constant dynamic. A lot of this relies of the height of the sstick, and force upon it. Hardest type. Again, lots of practice on a pillow will help, and metromone practice.
Buzz: Drop the stick on the drum head, allow it to die right away. Repeat with other hand. Trick is to release the other stick at exactly the right moment for the roll to sound consistant and stay at one dynamic. Easiest type. Only possible to practice on drum/pad.