Permutations for the Advanced Marimbist - 126 pages; Permutations For the Advanced Marimbist by Kevin Bobo is designed to give the marimbist a stronger and more fluid facility behind the keyboard through a process known as "downbeat displacement" This system will help the player literally understand a certain technique inside and out. In all there are a total of 129,600 different permutations possible with the through study and application of this method book.