Open, closed, open
Open, closed, open is a technique of playing snare drum rudiments, especially used during auditions or classical practice routines.
Technique
"Open, closed, open," also referred to as "open to close to open," or "slow, fast, slow," consists of beginning a drum rudiment very slow and controlled, speeding up evenly until at the maximum speed for the drummer, then slowing back down after maintaining that speed. Optimally, the drummer should end on the opposite hand as started, in case of alternating rudiments such as paradiddles. The speed at which the exercise ends should be the same speed as the exercise began. The time taken to accelerate to maximum speed should be equal to the time taken to decelerate to the beginning speed so that the exercise is symmetrical. The exercise should last one to two minutes with each individual rudiment, depending on the skill and stamina of the player, so that 30 seconds to one minute consists of acceleration and then a corresponding 30 seconds to one minute consists of deceleration.It is recommended that once a rudiment is learned, as far as the technical sticking and accents, that it be practiced regularly with the open, closed, open technique as well as at a moderate march tempo to ensure that a drummer or percussionist is able to play the rudiment accurately at any speed necessary for performance of musical repertoire.
The most difficult rudiments to play in this manner are those with continuous patterns such as the single stroke roll, double stroke roll, and triple stroke roll, due to the requirement for the sound to stay smooth and even while the technique used for playing the strokes changes with speed.