Plastic, in this research, deals with "direct access" to the material, as demonstrated in the "other" plastic arts. Painter's put their hands in the paint. Their vision adjusts the muscles and tension of their fingers and the signature of their strokes is recorded on canvas as their own performance of an idea.
It is a physical interaction with color and texture.

In studio composition, the composer is able to record the signature of his own movements at many levels of the studio process. The physical interaction of sound and body in continuous feedback loops through ear and hand is what brings the art of sound a step closer to the plastic arts.

Plastic Art