Final answer:
The composer adds markings for rhythm/movement (the rate of speed) and emphasis to help shape the expressive content of a work.
Step-by-step explanation:
The composer adds markings for rhythm/movement (the rate of speed) and emphasis to help shape the expressive content of a work. Rhythm in music is created through the use of patterns and repetition, which can give a sense of movement and pace. Emphasis, on the other hand, highlights certain elements in the music to draw attention to them.