system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is it about music that causes the brain to produce the physical urge to want to move our bodies? (dancing, foot tapping, head bopping, etc)
gpt
The auditory cortex of your brain is connected to the striatum, the part of your brain which is responsible for the pleasure and reward system. Dopamine, which also stimulates movement, is released when a good song comes on.

When your auditory cortex is stimulated, you are compelled to move to the rhythm of the song. Moving your body in a coordinated way along to the rhythm produces more dopamine.

This is all triggered by music due to an evolutionary adaption. Bipedal hominids walking through the grass survive better if they take their steps at the same time. This produces less constant noise which allows them to hear things around them better in the quiet between the group's coordinated steps. The reward center of the brain in turn reinforced this behavior.

Thus certain sounds make you feel good, such as the rhythmic steps of another person, and you find it pleasurable to move along to that rhythm.