open roll

A type of multiple bounce roll with typically less than three bounces per stroke. This roll is commonly used with a marching band or Drum and Bugle Corps in order for the rolls to have a clear and distinct sound in outdoor performance. This is also known as a measured roll. 

 

When performed as a rudimental drumming exercise, the roll would begin slow (or open) so one could count the individual bounces, then gradually increase in speed to one continuous sound (close), then gradually decrease in speed to where the bounces were again distinguishable (open).