Music is a combination of two non-obvious things
Music is one of the great unsolved scientific mysteries.
What is music?
Why should something like music exist at all?
Very often we can only solve a mystery after we discover some non-obvious thing that explains the mystery.
I have come to realise that music is explained not by one but by two non-obvious things.
Those two things are:
A glial illusion
Our ability to understand an obsolete prehistoric protomusical language of emotion
A glial illusion happens when glial cells in the brain observe the activity of neurons, and perceive a false value of some aspect of the neural activity.
Most illusions are neuronal illusions, in that it is the neurons that are doing the perceiving. But with a glial illusion, it is the neurons that are being perceived.
With a neuronal illusion, we are usually consciously aware of the false perception. For example, we might look at a pattern of lines printed on a piece of paper, and there is a false perception that the lines are moving, and we are consciously aware that they appear to be moving.
A glial illusion is non-obvious because there is no direct conscious awareness of the false glial perception - there can only be awareness of the effects of that false perception.
In the case of music, the glial illusion is that glial cells perceive an incorrectly low value for speech tempo.
Glial cells in the auditory cortex estimate speech tempo so that they can regulate the operating characteristics of those “downstream” neurons that process the meaning of speech. (This regulation is quite specific to processing speech, and the reason for this is that the meaning of speech is uniquely invariant under a time-scaling transformation, ie the meaning of a sentence is completely independent of how fast the sentence is spoken, so it makes sense to apply exactly the same speed adjustment to all the neurons involved in processing the content and meaning of the speech.)
The glial perception of tempo is quite separate from the neuronal perception of tempo that gives rise to our conscious perception of speech tempo or musical tempo.
You might think that if glial cells need to perceive tempo, and there are neurons for which their activity represents the perception of tempo, that the glial cells could just get that information from those neurons.
But in practice the glial cells have no reliable way to get that information from any neurons that might have it. Indeed the glial cells have no way of knowing or finding out which neurons represent which values of perceived tempo, or even which neurons represent the perception of tempo as opposed to the perception of something else.
(One known fact about brains is that specific functions are not always tied to any particular physical location or to any specific set of neurons - maps of functionality in the brain can “move around” over time.)
So the glial cells in the auditory cortex need to have their own separate means of estimating tempo which does not depend on knowing the specific meaning of the activity of any particular neuron. (These glial cells do “know” that they are observing neurons that are processing auditory information, because they are in the general brain region that processes auditory information, but their knowledge is not any more specific than that.)
This estimation method depends on observing how often neurons transition from a fully inactive state to a fully active state. This is a reasonable proxy for direct observation of speech tempo.
However music confounds this method of estimation because it contrives patterns of neural activity where some neurons are almost always active and other neurons are almost always inactive, and therefore the transitions from inactive to active occur much less frequently.
The result of these contrived patterns of neural activity is that music generates a false glial perception of a very slow tempo.
And the result of that false perception is that glial cells incorrectly regulate the operating characteristics of neurons downstream from the auditory cortex which are calculating and processing the meaning of speech, including the emotional consequences of that meaning.
This incorrect regulation, or dysregulation, results in an intensification of the calculated emotional responses of the meaning of speech.
This accounts for the intensity of musical emotion.
But the glial illusion does not account for the quality of musical emotion.
Also it does not account for why musical emotion should exist at all. Among other things, music isn’t actually speech, even though it shares some of the general auditory characteristics of speech.
This is where the second non-obvious thing comes into the picture.
The second non-obvious thing is our ability to perceive the emotional meaning of protomusic.
Protomusic was a prehistoric language of emotion. It was used as a means of communication by our prehistoric ancestors (maybe 2 million years ago - and the reason for this estimate relates to the possibility that protomusic evolved as an adaptation to support confrontational scavenging) to express shared emotion, ie something like “because of something in the current situation, we should all feel happy/sad/excited”.
We no longer hear protomusic. No one “speaks” protomusic any more. Protomusic is obsolete. Modern word-based spoken language has completely replaced it.
But, even though protomusic no longer exists to be heard, we still retain the ability to understand it.
Our ability to understand the emotional meaning of music totally depends on our ability to understand the emotional meaning of prehistoric protomusic, because music is an illusory form of protomusic, that is, music is protomusic which has been altered to generate the glial illusion which intensifies the perceived emotional meaning of the protomusic.
So what did protomusic sound like?
If we heard plain non-illusory protomusic today, it would sound like music which wasn’t musical.
It would have the recognisable emotional meanings of music, but the perceived emotions would not be intense like those of music.
Protomusic would not have the features of music that cause the glial illusion. For example it would not have pitch scales, or harmonic intervals, or precise regular beats.
In its original form, protomusic was used to communicate pragmatically.
Music can create a strong feeling that something is being communicated, but, we don’t actually use music to communicate in a practical sense.
This suggests that, although we retain the ability the understand the emotional meaning of protomusic, something in our brains has evolved in a way that has switched off our willingness to process this perceived emotional meaning as if it was being communicated to us in the same way that we process the meaning of speech that we hear, for example, when we are in a conversation with someone.
For a more detailed discussion of this theory of music, and for the latest updates, see my “What is music?” blog at https://whatismusic.info/blog/.