Deviation from the Exact

This chapter focuses on performance. It asks: what does it really mean to perform a piece of music? What is it that a performer is ‘adding’ to make a musical score ‘come alive’, and sound musical and expressive? It argues that expression derives from five main sources, collectively referred to as the GERMS model: generative rules (G) that mark the structure in a musical manner; emotional expression (E) that serves to convey emotions to listeners; random fluctuations (R) that reflect human limitations in motor precision; motion principles (M) which hold that tempo changes should follow natural patterns of human movement, such as gestures; and stylistic unexpectedness (S) that reflects a performer's deliberate attempt to deviate from stylistic expectations regarding performance conventions to add tension and unpredictability to the performance.