This Video demonstrates how to Play the Flam Drum Rudiment. Flam Drum Rudiment Defined from the Dictionary: A drumbeat consisting of two almost simultaneous strokes of which the first is a very rapid grace note. (Music, other) a drumbeat in which both sticks strike the head almost simultaneously but are heard to do so separately.
The Video Explains how to play the Double Stroke Roll, which is considered the second drum rudiment. It is played by striking the Drum Head 2 times on each hand. If you perfect this rudiment it is possible to speed up to the speed of a buzzroll