This interview is based on an episode of the podcast “Talk that Science” – an initiative started by students from the University of Amsterdam. Listen to the episode here (in Dutch).
In 1984, a curious study on musicality in animals was published. The researchers from Portland, Oregon trained pigeons to distinguish two pieces of music – one by Bach, the other by Stravinsky. If the birds got it right, they were rewarded with food. Afterwards, the same pigeons were exposed to new pieces of music from the same composers. Surprisingly, they were still able to determine which piece was composed by which composer.
This finding confronted researchers with a new set of questions. To what extent are animals musical? What does it even mean for an animal to be musical? And what can this teach us about musicality in humans? We will discuss these questions with Henkjan Honing, professor in Music Cognition at the University of Amsterdam.
Henkjan, what exactly is music cognition?
Henkjan Honing: Music cognition is a set of tools to understand our capacity for music, or musicality for short. We use methods from psychology (conducting listening experiments), computer science (developing computational models) and music theory. Since recently, we also involve methods from biology to study the biological basis and mechanism of musicality. You see it’s a very broad toolkit. But ultimately, it is about cognition – which happens the brain.
You started as a pianist and you were active as composer for a while. But ultimately you ended up in science. How come?
My family is musically very active. But when I grew up, the first computers and synthesizers were made, and they fascinated me. I believed that synthesizers would be the future and pianos were old-fashioned. One day I sold all my instruments and bought one of the first computers with which you could makes sounds. I started studying computer music at Stanford in the US. At the time, I was still a composer, because my goal was to make music with these machines. I believed everything was possible with a synthesizer. Any sound would be possible to make. But as you can imagine, it turned out differently.
When did you move from composing to science?
At some point, I got a commission to create a composition for two percussionists. But I wanted to take it a step further and create a listening machine. The idea was the following: there were two percussionists with headphones, who could not hear each other. The computer listened to what they played and let the percussionists know through the headphones what they should be playing. The percussionists started playing two random rhythms, without knowing what other one was playing, and the computer would guide them to play the same rhythm.
This meant that I needed to explain the computer what the ‘downbeat’ of the rhythm was. This is something any musician would know intuitively, but I had to tell the computer explicitly. It turned out a lot harder than expected.
How can you extract the pace of the music from the acoustic signal? I realized that this information is not only contained in the signal itself, but partly in the musician’s mind. That was a big surprise for me. You can make any sound you like, but that’s not enough. The expectations of the listener are what makes listening such a nice experience.
Currently you are not focusing on computers anymore. Your book The Evolving Animal Orchestra is about musicality in animals. How did you move from computers to animals?
This was due to a discovery I made around 2009. Together with Hungarian researchers I did experiments with newborns to investigate to what extent they can differentiate rhythms. It turned out that newborns already have beat perception – they were surprised when I suddenly changed the rhythm. I previously believed that beat perception was something cultural – something you learn from your parents or while dancing. But these experiments suggested that humans are born with beat perception. This sparked my interest in biology. I wondered: is this something unique to humans, or do other animals have this as well?
We are inclined to say that birds are musical animals. But this says more about us than about those birds.– Henkjan Honing –
Going back to the research about the pigeons, who could distinguish music from Bach and Stravinsky. Can conclude from this experiment that pigeons possess musicality?
I don’t think so. The pigeons simply learned a specific feature of the music, which enables them to distinguish the sound that gives them food from the sound that does not.
You can compare it to this scenario: say you want to have an algorithm that recognizes airplanes on a picture. You can implement a lot of difficult rules to be able to do that. However, you can also design an algorithm that simply checks whether there is a small black point beneath the nose of the plane: a nose wheel. In 90 percent of the cases the algorithm will correctly recognize airplanes. This is similar to what the pigeons do. They recognize details that will deliver food. That has not much to do with musicality.
It only shows that they can listen?
It shows that they can listen and that they have cognitive abilities such a memory and classification. But it also pointed the way for further research. First, we do not know exactly what the pigeons listen to, so we should design experiments to find this out. Second, we need to specify more clearly what musicality is.
When do we call an animal musical? We are inclined to say that birds are musical animals. But this says more about us than about those birds. The interesting question is: what is music for an animal? Can musical sounds make animals happy or excited?
Interesting. So we should not ask whether the animals can understand or produce what humans call music. We should ask if animals also experience sounds as music. Is that right?
Yes, Darwin wrote that the pleasure of perceiving melody and rhythm must be something we share with all animals.
Do you agree with Darwin on that point?
I think melody and rhythm are still a very broad terms. When you play the same melody on two different instruments, humans still perceive them as the same melody, even though their timbres differ. But for birds, this is not the case. Humans focus more on melody, while birds focus more on differences in timbre.
Which aspects of musicality are important for all animals?
This is a fascinating question. Apparently, we can switch: in speech, we focus a lot on changes in timbre, while in music we don’t. It’s not clear how our brain adapts to these two different contexts of listening. It seems that we have various listening modes. Maybe birds can also focus on melody, but for their survival, it’s apparently not important. A lot of open, interesting questions!
What are some questions are already answered? Which animals have you found that have beat perception?
Snowball, the dancing cockatoo was the first animal to be found with beat perception. This finding boosted our research field. Both cockatoos and humans can perceive and synchronize to a beat (BPS), but monkeys can’t. What do we share with cockatoos that we do not share with monkeys? One prevalent theory was that it had to do with vocal learning.
Vocal learning means that you have enough control over your speech to produce new sounds. Monkeys can’ do that. And most birds can’t do it either: they can just sing one song and that’s it. However, certain bird species can imitate sounds, even sounds of cameras or machines. For a long time, researchers thought that vocal learning was a prerequisite for beat perception.
But beat perception and imitating sounds sound like two very different abilities.
A lot of research has been conducted with birds on vocal learning, because it seems a prerequisite for learning a language. But one researcher, Ani Patel, believed it was also a prerequisite for beat perception in music. And indeed, a cockatoo was found who had both vocal learning and beat perception.
The nice thing about such a theory is that you can falsify it. You only have to find one animal with beat perception but without vocal learning, and then you know the theory is not true, at least not generally.
And such an animal has been found?
We had to search for a while, but in 2013 colleagues from the University of California Santa Cruz found it: a Californian sea lion. You can imagine that everyone in the field was excited and confused about this finding. The underlying mechanism still remains an open question.
I read in your book that you have conducted research on beat perception in rhesus monkeys. Can you tell me something about that?
It was hard to start research on musicality in rhesus monkeys. I wanted to use the same method I used in the experiment with newborns – sticking electrodes on their head and measuring EEG. Research on rhesus monkeys, however, is usually invasive – the electrodes go into their brains. I don’t find this method suitable for musicality research. For biomedical purposes you might be able to justify it, but musicality is not that important.
Many researchers in the field said that the non-invasive method was not possible and had never done before. It’s rather odd that I, as an amateur, come into this new research field proposing a new method. After a lot of effort, I found one study where they had used EEG and finally, I could run my experiment.
And what did you find?
It turned out that rhesus monkeys have no beat perception. This surprised me. Rhesus monkeys are a well-known animal model for humans, because our brains are so similar. Therefore, I think that the difference is not so much in the structures themselves, but more in the connections between them.
It seems strange that humans and cockatoos have beat perception, but monkeys that are so similar to us don’t.
Indeed, I still don’t believe it. And others do not either: many people conjecture that the experiment was not well conducted. A Japanese lab jumped in and did a behavioral experiment with chimpanzees. They found that chimpanzees spontaneously start moving to music.
Strictly speaking, you cannot call it dancing, but rather rhythmic swaying. Male chimpanzees do it more than females. They use it to show that they are in charge. This finding shows that, recently in evolution, beat perception and synchronization has played a role.
Could you say that the chimpanzees enjoy music and that’s why they dance?
It is hard to show if they enjoy it. At least, they are excited. But joy is hard to interpret from behavior.
The experience of music
Suppose you find out everything about music in the brain – do you think you will be able to predict everything about musicality?
Only talking about brains is obviously a simplification. Of course, the body as a whole plays an important role as well. And how someone listens crucially depends on the culture he or she comes from.
Moreover, understanding something does not mean that you can reproduce it. I don’t think I will be able to make a very popular song on the basis of science. This is not even my aim. My aim is understanding.
And what about you, do you still enjoy music with all the knowledge in your mind?
Yes! I quit playing music myself, as I get irritated by the mistakes I make. But I still really enjoy listening to music. My work on musicality operates on a different level than the listening to music.
This seems to show that the experience of music is fundamentally different from the theoretical knowledge about music.
Unless you have a theory about the experience of music.
But a theory of experience is still not the experience itself.
That’s true. Experience is one of the most essential things when it comes to music. It’s exactly that part of music theory that I don’t dare to involve myself in.
Is there something else you would like to say about your research on musicality?
Yes. Everyone is musical. We should realize that we can do a lot as listeners. And that our listening history has a big influence on how you perceive music. Two people who made different experiences hear different things. Do not say that you are not musical because you are not good at playing an instrument, while you do have big CD collection in your house. The ability to enjoy music is special, and hard to trace in the animal world.
Nicolien Janssens was asking the questions in this interview.
Want to know more? Check out this related lecture by Henkjan Honing in Paradiso, Amsterdam.
Find more information on Henkjan Honing’s Music Cognition research group here.