Getting to the Root of How Humans Understand Music
There is something about music that can hit the spot or make us feel a certain emotion. Those with untrained ears can pick up on slight variations in chords and melodies, even if they cannot always articulate the differences. It also seems that humans often share similar emotions and associations evoked by listening to the same music. Decades of research in the area of music acquisition and understanding back up these gut feelings.
To introduce this topic, it helps to first understand a bit of music theory. There are 12 notes in Western music, and they can most clearly be seen on a piano, where they are arranged in a repeated pattern. Out of these 12 notes, every major and minor scale is comprised of a seven-note subset. Each of those scales revolves the tonic, or the first note in the scale. The tonic note feels like home to a listener. That is, we instinctively want music to resolve, or land back at home, by ending on the tonic.
Music is made by using notes from a scale to create melodies — notes strung together horizontally over time, like a line that you can sing — and harmonies — notes stacked vertically and played at the same time to create a chord. In a chord, the root is structurally the most significant pitch and sounds the most prominent. Because the root is the basis of a chord, it also gives the chord its name. The root at any point in a song can change to make the music sound more interesting while the tonic remains the same.
In a chord, the root is structurally the most significant pitch and sounds the most prominent.
The tonic is so important that musical compositions based on the tonic’s scale are labeled based on the key of the tonic. It follows that compositions typically begin and end with a note in the tonic chord.
An influential study published in Perception & Psychophysics in 1994 found that implicit knowledge of varying aspects of musical structure developed at different ages in children. The researchers demonstrated that by the age of 5, children exhibit understanding of key membership — essentially, which notes sound like they belong with a given tonic. While children at this age did not not perform as well on recognizing implied harmony — a prototypical accompaniment to a melody, 7-year-olds and adult participants showed implicit knowledge of both.
A 2005 study in Developmental Science with slightly older participants, 6- to 11-years old, affirmed that children in Western-influenced countries had implicit understanding of common musical properties even without training. Each child heard a series of chords followed by a final chord. The final chord was either the tonic, the chord best suited to resolve a musical phrase, or a less stable chord. In one experiment, French children guessed if the target was sung with one of two vowel sounds. In another, Australian children guessed if the target was played on a piano or trumpet. In a third experiment, Canadian children guessed whether the target sounded harmonious or discordant. In all groups, performance was faster when the target was the tonic chord. Performance was also more accurate for the Canadian children with the tonic as the target.
A 2005 study in Developmental Science with slightly older participants, 6- to 11-years old, affirmed that children in Western-influenced countries had implicit understanding of common musical properties even without training.
One theory for how humans acquire such knowledge about music structure is based on the statistical properties of music. For instance, notes in a tonic chord may be more recognizable because they occur more frequently in a given composition than other notes in a scale. However, this theory of relative frequency of occurrence may be limited to explaining only some aspects of musical structure due to conflicting research findings. The Perception & Psychophysics study, for example, found that children seem to develop knowledge of key membership before implied harmony. But harmonic accompaniment is already present in music that young children are exposed to, such as TV show theme songs.
Much work has been done studying implicit understanding of Western musical concepts, especially in children. But there are still many more potential areas of further research on how the human brain understands and is affected by music. For the majority of music lovers, though, it’s enough that a song just feels right. As American poet Henry Wadsworth Longfellow put it, “Music is the universal language of all mankind.”
DOI: 10.3758/BF03213891
DOI: 10.1111/j.1467–7687.2005.00447.x
