Music therapy involves working with a trained professional who uses musical experiences—usually in a one-on-one or group setting—to help lift depression, reduce anxiety, or achieve other health goals. That's different than "music medicine" which can be done solo: just turn on a playlist and listen. An array of scientific studies now show that music medicine is highly effective and helping treat hypertension, depression, anxiety, and even reduce physical pain.
Music medicine may work its magic through a range of mechanisms. While it might seem obvious that happier tunes can get you out of a rut of negative thinking, many people who feel sad also benefit from listening to something melancholic. It's possible that these pieces help us to accept our feelings without fighting them, which is often important for recovery. Depending on the track, we might feel a sense of connection with the artist's expression of the emotions we are encountering, which could lead us to recognise the shared humanity in our suffering – a prerequisite for self-compassion – and allow us to find meaning in what we are experiencing.
At a physiological level, low-tempo tracks could help to entrain the electrical activity in the brain stem to slower rhythms, which can bring about a more tranquil mood and regulate other biological processes – such as heart rate and respiration. Repeating musical motifs, producing a buildup and release of tension, are also known to play with the brain's prediction and reward circuitry. This can trigger the release of neurotransmitters such as dopamine and endogenous opioids, which ease both emotional and physical pain. At its most extreme, we may feel these neurochemical changes as musical frisson or "chills" – an intense aesthetic experience.