Final answer:
Jimmy displayed rebellious behavior at the music summer camp by refusing to participate in group activities and failing to practice his scales during music practices.
Step-by-step explanation:
Two incidents where Jimmy displayed rebellious behavior at the music summer camp were:
- During group activities, he refused to participate and instead chose to be pouty and grumpy.
- During music practices, he failed to pay attention and refused to practice his scales.
Despite his bad attitude, Jimmy did not bother anyone else with his behavior.