Consonant intervals and dissonant intervals are processed via separate mechanisms in the auditory cortex. Recent results from studying the electrophysiological responses of humans and monkeys to sensory dissonance that is, chords that sound dissonant by virtue of their frequency ratios, not due to any musical context show that neurons in the primary auditory cortex the first level of cortical processing lieve that mothers helps to call the babies’ attention to the mother’s voice, and helps to distinguish words within the sentence. Instead of saying, as we would to an adult, “This is a ball,” mothers would entail something like, “Seeeeee.
In such utterances, the contour is a signal that the mother is asking a question or making a statement, and by exaggerating the differences between up and down contours, the mother calls attention to them. In effect, the mother is creating a prototype for a question and a prototype for a declaration, and ensuring that the prototypes are easily distinguishable. When a mother gives an exclamatory scold, quite naturally and again without explicit training she is likely to create a third type of prototypical utterance, one that is short and clipped, without much pitch variation: “No!” (Pause) “No! Bad!” Babies seem to come hardwired with an ability to detect and track contour, preferentially, over specific pitch intervals.
Trehub also showed that infants are more able to encode consonant intervals such as perfect fourth and perfect fifth than dissonant ones, like the tritone. Trehub found that the unequal steps of our scale make it easier to process intervals even early in infancy.
From prior work, it is believed that nine-month-olds have not yet incorporated a mental schema for the major scale, so this suggests a general processing advantage for unequal steps, something our major scale has. In other words, our brains and the musical scales we use seem to have coevolved. It is no accident that we have the funny, asymmetric arrangement of notes in the major scale: It is easier to learn melodies with this arrangement, which is a result of the physics of sound production the set of tones we use in our major scale are very close in pitch to the tones that constitute the overtone series.
Very early in childhood, most children start to spontaneously vocalize, and these early vocalizations can sound a lot like singing. Babies explore the range of their voices, and begin to explore phonetic production, in response to the sounds they are bringing in from the world around them. The more music they hear, the more likely they are to include pitch and rhythmic variations in their spontaneous vocalizations.
Young children start to show a preference for the music of their culture by age two, around the same time they begin to develop specialized speech processing. At first, children tend to like simple songs, where simple means music that has clearly defined themes (as opposed to, say, four-part counterpoint) and chord progressions that resolve in direct and easily predictable ways. As they mature, children start to tire of easily predictable music and search for music that holds more challenge.
According to Mike Posner, the frontal lobes and the anterior cingulate a structure just behind the frontal lobes that directs attention are not fully formed in children, leading to an inability to pay attention to several things at once; children show difficulty attending to one stimulus when distracters are present. This accounts for why children under the age of eight or so have so much difficulty singing “rounds” like “Row, Row, Row Your Boat.” Their attentional system specifically the network that connects the cingulate gyrus and the orbitofrontal regions of the brain cannot adequately filter out unwanted or distracting stimuli.
Children who have not yet reached the developmental stage of being able to exclude irrelevant auditory information face a world of great sonic complexity with all sounds coming in as a sensory barrage. They may try to follow the part of the song that their group is supposed to be singing, only to be distracted and tripped up by the competing parts in the round. Posner has shown that certain exercises adapted from attention and concentration games used by NASA can help accelerate the development of the child’s intentional ability.
The developmental trajectory, in children, of first preferring simple and then more complex songs is a generalization, of course; not all children like music in the first place, and some children develop a taste for music that is off the beaten path, oftentimes through pure serendipity.
“The Teddy Bear’s Picnic,” and “Bibbidy Bobbidy Boo” songs that were made for children. But sufficient exposure to the relatively exotic chord patterns and voicings of Frank de Vol’s and Leroy Anderson’s orchestras became part of my mental wiring, and I soon found myself listening to all kinds of jazz; the children’s jazz opened the neural doors to make jazz in general palatable and understandable. Researchers point to the teen years as the turning point for musical preferences.
It is around the age of ten or eleven that most children take on music as a real interest, even those children who didn’t express such an interest in music earlier. As adults, the music we tend to be nostalgic for, the music that feels like it is “our” music, corresponds to the music we heard during these years. One of the first signs of Alzheimer’s disease (a disease characterized by changes in nerve cells and neurotransmitter levels, as well as destruction of synapses) in older adults is memory loss. As the disease progresses, memory loss becomes more profound. Yet many of these old-timers can still remember how to sing the songs they heard when they were fourteen.
Part of the reason we remember songs from our teenage years is because those years were times of self-discovery, and as a consequence, they were emotionally charged; in general, we tend to remember things that have an emotional component because our amygdala and neurotransmitters act in concert to “tag” the memories as something important.
There doesn’t seem to be a cutoff point for acquiring new tastes in music, but most people have formed their tastes by the age of eighteen or twenty. Why this is so is not clear, but several studies have found it to be the case. Part of the reason may be that in general, people tend to become less open to new experiences as they age. During our teenage years, we begin to discover that there exists a world of different ideas, different cultures, and different people.
We also seek out different kinds of music. In Western culture in particular, the choice of music has important social consequences. We listen to the music that our friends listen to. Particularly when we are young, and in search of our identity, we form bonds or social groups with people whom we want to be like, or whom we believe we have something in common with.
As a way of externalizing the bond, we dress alike, share activities, and listen to the same music. Our group listens to this kind of music, those people listen to that kind of music. This ties into the evolutionary idea of music as a vehicle for social bonding and societal cohesion. Music and musical preferences become a mark of personal and group identity and of distinction.