Final answer:
Music therapy prompts the release of endogenous opioids during the modulation stage of the pain process.
Step-by-step explanation:
The release of endogenous opioids during the pain process occurs during the modulation stage. Music therapy works by stimulating the release of endorphins, which are a type of endogenous opioid, in the brain. These endorphins help to reduce pain perception and provide relief from chronic pain.