What explains the magic of Grammy winner Adele's song called "Someone Like You"? Though personal experience and culture play into individual reactions, researchers have found that certain features of music are consistently associated with producing strong emotions in listeners. Combined with heartfelt lyrics and a powerhouse voice, these structures can send reward signals to our brains that rival any other pleasure.
Twenty years ago, the British psychologist John Sloboda conducted a simple experiment. He asked music lovers to identify passages of songs that reliably set off a physical reaction, such as tears or goose bumps. Participants identified 20 tear-triggering passages, and when Dr. Sloboda analyzed their properties, a trend emerged: 18 contained a musical device called an "appoggiatura."
An appoggiatura is a type of ornamental note that clashes with the melody just enough to create a dissonant sound. "This generates tension in the listener," said Martin Guhn, a psychologist at the University of British Columbia who co-wrote a 2007 study on the subject. "When the notes return to the anticipated melody, the tension resolves, and it feels good."
Chills often descend on listeners at these moments of resolution. When several appoggiaturas occur next to each other in a melody, it generates a cycle of tension and release. This provokes an even stronger reaction, and that is when the tears start to flow.
To learn more about the formula for a tear-jerker, a few years ago Dr. Guhn and his colleague Marcel Zentner found musical excerpts—from Mendelssohn's "Trio for Piano" and Barber's "Adagio for Strings," for example—that reliably produce the chills and then measured the physiological reactions (heart rate, sweating, goose bumps) of listeners.