Instrument Design

Good instruments don't have a lot of variables in the the sound. A saxophone or guitar have only the notes that control pitch. Their systems of sound production are essentially very simple, a vibrating string or the harmonic of air in a tube.

They do have a lot of inputs to controls the single variable that controls the sound. Guitarists have many ways to strum the string, or hold down the string on the neck. Sound is still produces the same way, but the different ways of reaching this same goal, make for expressiveness.

This is the ultimate goal of instrument design. The music's ultimate goal is not notes but expression.