Why do minor chords sound sad?

Minor chords sound sad to us partly because they echo the sound of a sad voice, and partly because we have learned, over a lifetime of songs and film scores, that minor means sorrow.

The difference between happy and sad is tiny. A C major chord is C, E and G. Lower the middle note by one semitone, the smallest step on a piano, to E flat, and you get C minor: C, E flat, G. That lowered interval, the minor third, is what gives minor chords their name, and their colour is often described as darker. Listeners also tend to hear minor chords as slightly more dissonant, which nudges them towards negative feelings.

Part of the effect seems to come from speech. When people speak sadly, their voices produce a tone close to a minor third, and one theory holds that music moves us by imitating the sounds and movements of human emotion. Some links really do seem built in: across young children and isolated cultures, low and slow sounds sad while fast and high sounds happy.

But the major-happy, minor-sad link itself looks mostly learned. Cross-cultural studies suggest that people pick up these associations from the music around them, and they pick them up early: children as young as three can already call a piece happy or sad from its mode alone.

And sad music is not a punishment. Listeners often say minor-key songs bring comfort, nostalgia or relief rather than real sadness.