Final answer:
The extended metaphor of fireworks as performers creates a celebratory tone.
Step-by-step explanation:
The extended metaphor of fireworks as performers creates a celebratory tone by associating fireworks with entertaining dancing and music. The passage describes fireworks as performing pirouettes on night's stage and playing Lady Liberty's song like percussionists. These vivid descriptions create a sense of excitement and joy, supporting the celebratory tone of the passage.