How can music create emotion?

How can music create emotion?

How can a sequence of vibrations feel joyful, tense, or mournful when the sounds themselves do not describe an event? A photograph of a funeral has a subject. A sentence makes a claim you could disagree with. A chord does neither — it asserts nothing, depicts nothing, and yet people weep at it. Perhaps the feeling arises partly from what the mind expects those sounds to do next.

Start with something small and hard to deny. As we listen, the brain continuously predicts timing, melody, harmony, and intensity — not deliberately, but the way it predicts the next step of a staircase in the dark. Music can satisfy those predictions, delay them, or overturn them. A delayed resolution creates tension; its arrival can feel like relief. Repetition gives us a pattern, while variation keeps the pattern alive.

Now push on that. If emotion came from surprise alone, a piece should stop moving you the moment you know it — and it plainly does not. Familiar music often moves people more. So prediction cannot be a single yes-or-no event resolved once and discarded. What would have to be true instead?

Something like this, which is roughly what Leonard Meyer argued in 1956: the feeling lives not in the outcome but in the tendency — an expectation set in motion and then held, inhibited, made to wait. David Huron later split that moment into parts, distinguishing what happens before an event (imagination, and the body's tensing in readiness) from what happens after it (a fast reflex, and then a slower appraisal). That split is the useful bit, because the two halves need not agree. The reflex does not learn. A sudden entry still jolts you the hundredth time, while the appraisal arriving a beat later says of course, I knew that was coming — and the pleasure seems to live in the gap between the startle and the reassurance. Which is why knowing a piece well does not disarm it, and may be the condition for enjoying it.

Rhythm recruits the body more directly. We anticipate beats, adjust attention around them, and may synchronize movement and arousal with them. Loudness, tempo, and timbre shape that bodily state — faster and louder generally means more aroused, which is the closest thing to a reliable rule here — but arousal is not an emotion. It is a dial, not a word: the same quickened pulse serves excitement and dread, and what settles which one you feel is largely everything else in the piece.

Is there anything measurable underneath all this? The clearest evidence comes from chills — the shiver some listeners get at particular moments, which is convenient for researchers precisely because the listener can point at the second it happens. Salimpoor and colleagues found dopamine release in the striatum at those peaks, and, more interestingly, in anatomically different places for the anticipation and for the moment itself. Notice what that does and does not settle. It says music engages the same reward machinery as food or money, which is not nothing. It does not say why these notes, in this order, do it to this person.

Personal memory adds the last layer. A song heard during an important experience can later reactivate some of that emotional setting — and once it can, no account of the notes alone will predict what the song does to that listener. So are we hearing emotion inside the music, or are music, prediction, body, culture, and memory creating it together?

There is no universal code in which every minor chord means sadness and every major chord means joy. This is worth stating flatly because the opposite is taught. Some cues do seem to travel: listeners with little exposure to Western music can often sort unfamiliar Western pieces into something like happy, sad, and frightening at better than chance, and those judgements lean heavily on tempo and loudness — the arousal dial, which is close to physiological. The mode-to-mood mapping is the part that does not travel well. A great deal of Balkan, Greek, and klezmer dance music sits in modes a Western ear reads as minor, and no one at the wedding is hearing mourning.

Two honest qualifications about the mechanism itself. First, expectation is one route, not the route. The leading multi-mechanism accounts list several parallel ways music reaches a listener — a brain stem reflex to sudden loud or dissonant sound, entrainment to rhythm, associations built by simple conditioning, contagion from a voice-like line, imagery, autobiographical memory, expectancy, and aesthetic judgement — and which of them dominates varies by piece, listener, and occasion. Second, there is a genuine and unresolved argument about whether listeners feel the emotion or merely recognize it in the music, and the two are hard to distinguish from a questionnaire. The effect is real and reliably reproduced; the explanation for it is still contested, and any account that sounds tidy is leaving something out.

• Why musical tension can be enjoyable.
• How film scores guide interpretation of a scene.
• Why familiar songs can trigger unusually vivid memories.

Every term the collection defines is gathered in the glossary.