On her last night at the hospital after undergoing a series of spine surgeries, Susan Mandel lay in bed listening to Pachelbel's Canon in D.
For days, Mandel's positive attitude had kept any anxiety at bay, so she was surprised when she noticed her face was wet. She sobbed silently, listening to the familiar violins, until the tears stopped coming. Then she felt peace.
"It wasn't a cry of anguish, it was a cry of relief," Mandel said, recalling the night more than 20 years ago. "It's very tender, evocative music, and I think it gave me permission to release the pent-up emotions."
Philosophers for millenniums have marveled at the power of music to speak to our souls, to inspire joy, melancholy, aggression or calm with visceral insight beyond the grasp of our rational minds.
Thanks to advances in neuroscience, researchers are beginning to understand what it is about music that touches us so deeply, and how to harness that power to soothe, uplift, comfort and heal - to use music as medicine for emotional and physical health.
Mandel, a music therapist and research consultant at Lake Health Wellness Institute in Cleveland, this month released "Manage Your Stress and Pain Through Music," (Berklee Press Publications), with co-author Suzanne Hanser, chairwoman of the music therapy department at Berklee College of Music in Boston. The book explains how to choose and use music to cope with challenges in your life.
It's not just tempo
It can seem obvious which songs would bring you up and which might bring you down. And indeed, there are structural components to songs that are meant to communicate joy, such as a fast tempo in major mode, or sadness, such as a slower tempo in minor mode.
But there's a difference between the emotion communicated through music and the emotion actually induced in the listener. Our memories, personal preferences and mood at the time can have a heavier influence than the intent of the musical structure in how music makes us feel.
"You could have a really positive emotional experience with a song that structurally communicates sadness," said Meagan Curtis, assistant professor of psychology at State University of New York at Purchase, who does research in music psychology.
What matters most in reaping the health benefits of music, from pain reduction to stress relief, is that you listen to music you enjoy, research shows. In a study on cardiac rehabilitation patients, Mandel found that the patients who liked a therapeutic music CD she put together experienced a reduction in blood pressure and reported feeling calmer, while patients who didn't like the music felt worse.
While there are structural components that convey soothing, such as consonant harmonies and a narrow pitch range, whatever music has the most positive associations to the individual will have the most positive emotional and physiological response. It activates the parasympathetic nervous system, which calms heart rate, lowers blood pressure and relaxes muscles.
"I have found people who love punk rock and find that it helps them to sleep," Hanser said. "It's likely that they have learned it truly speaks to them and expresses a part of who they are."
Help us tolerate pain
Music also has been found to help people tolerate pain longer and to lessen the pain.
That could be because people take comfort in the familiar, or because it distracts them. Between recalling memories, tapping our fingers, conjuring up images and other tasks, our brain releases so many chemicals to process music that they interfere with our perception of pain.
There's some evidence that we feel music viscerally because it goes straight to the amygdala, the part of the limbic system that manages our emotions, and the hippocampus, where long-term memories are stored, Hanser said.
Music that gives people chills or shivers up the spine has been found to activate the same reward areas of the brain stimulated by food, sex and certain types of recreational drugs, Curtis said. While different people get chills from different songs, often those shiver-producing songs have an unexpected tonal structure, like a chord that isn't part of the harmonic progression, she said.
People know what works
While structure is less important than personal experience in a song's ability to induce emotion, lyrics may be even less important than structure, Curtis said. We don't need to consciously attend to structure to process its emotion, but we do have to pay attention to lyrics, making the impact of structure stronger and less difficult to process.
People are usually very intuitive about what songs are useful to them and often choose music appropriate for the state they're in, Curtis said.
That explains one of the great ironies of human behavior: that many people like to listen to sad music when they're sad.
We might like the affirmation, as we create a bond with the singer or composer because they, too, have felt what we feel, Curtis said. Another theory is that wallowing is a kind of emotional catharsis, helping us fully experience the sadness so that we go through the stages of grief more quickly.
And it can be a healthy thing. A central tenet of music therapy is to meet people where they are, called the ISO principal. So if people are very depressed and lonely, you would start them with music that matches their mood before introducing something more uplifting.
"You first affirm and allow the person to reflect, and then move on to more positive things and hopeful outlooks," Hanser said.