The element of improvisation is the thing that distinguishes a drumcircle from a drum class or drum ensemble. A drumcircle is a forum for group improvisation. A drum Class may teach improvisation skills alongside rhythms and drumming techniques. A drum ensemble may create arrangements with improvised sections and elements in the creation of a performance.
In a drumcircle the starting point is improvisation. In a facilitated drumcircle you may get some skills teaching as in a class and some orchestrated elements similar to a drum ensemble but the backdrop is always improvisation and the group creating the material themselves.

This diagram illustrates that all three elements are present in varying amounts in all three types of drumming event.
In DrumCrazy we use the improvised drumcircle as the starting point for everything. From that can be born a whole range of different programmes for different situations. Elements of drum class and drum ensemble will be drawn in as appropriate to the particular group we are working with.