A performance can either be rehearsed or improvised. Improvisation is a musical idea created on the spot (such as a guitar solo or a drum solo), with no prior premeditation, while rehearsal is driving repetition of an feeling until it unfashionable achieved cohesion. Musicians will generally add improvisation to a well-rehearsed approximation to dream up a unique performance.
Notated music is produced as sheet music. To perform rock-and-roll from notation requires an understanding of both the musical style and the performance system that is associated with a piece of measure or genre.
