In the era of the never-ending playlist, when tunes are almost too algorithmically available, these writers remind that a regular appointment of conscious listening, playing or singing can be better than a visit to the clinic.

Of course Schubert might not be the right prescription, and finding the proper dose takes experimentation. Why is it that one Bach suite calms a teenager with severe autism, while another incites him to punch a hole through her cello?

Listening to Edith Piaf in Oppert’s presence, a 65-year-old man with A.L.S., a former boxer, removes his oxygen mask to sing along and proclaim: “I’m in the ring. I’m strong enough to fight!”