Daniel Levitin

Daniel Levitin: One of the things about musical memory is that, in some respects songs stick in our head, and maybe that’s because they’re supposed to. It’s difficult to talk about these things without talking about evolution. When you can remember a song so well, maybe it suggests that evolution wants us to. Maybe songs played an important role in our evolutionary history. A lover out on a hunt for a long period of time wants to be remembered while he’s away, she wants him to remember her, they have their song that they sang to each other, and, you know, that sticks in the head, and it keeps them faithful, and, you know, there’s some evolutionary advantages in that, in terms of raising the kids and, and so on. I’m interested in what attributes of music stay stuck in the head. Is it rhythm, it is pitch, what is it? It turns out to be all of it.  The average person has an extraordinary memory for the components of music. Even when there’s no theoretical reason why they should.  So, take the song “Happy Birthday”. Every time you sing it, you sing it in a different key. It’s still the same song. Whoever it is that’s in the room that starts, they just start any way they feel like, they may not even think ahead. And then you all join in, and some of you are synchronized in the right pitch, and some of you aren’t, and it doesn’t really matter. It’s still the same song.

In fact, it was the Gestalt psychologists, who noticed in the 1890s, Christian Von Ehrenfels and Max Wertheimer and others, that there’s this funny property to songs. You can sing them with any group of notes, and they’re still recognizable as the same song. Even when you change every single note, it’s still the same song.

It’s because songs are defined by the relationship between pitches, not the absolute pitches. Nevertheless, if you ask the average person in the street to just sing their favorite song, they tend to sing it with the right pitches. Their memory has encoded this information that isn’t necessary for maintaining the identity of the song, but it’s there.  Why would evolution create a brain mechanism that holds onto the stuff that it doesn’t need? It must’ve been important, throughout evolutionary time, or it must be that memory is more efficient, if it can hold onto all this detail. People don’t just remember the absolute pitches, but they tend to remember the actual tempo, and a lot of the little nuances of the singer’s voice. When Michael Jackson goes, “Eeh, eeh!” or Madonna has a particular growl in her voice, people remember all of that, and they replicate it when they sing.

So describe how you do this experiment to study this.

One of the ways that, that we study this is we just bring people into the laboratory, or stop them on the street. We ask them to sing their favorite song. And then we analyze their production, and compare it to the CD. Now, in order for this to work, they can’t be singing a song like “Happy Birthday”, or the National Anthem, or “Deck The Halls”, where there is no right key. But if they sing a pop song, a song by U2 or by Backstreet Boys, that song exists in the world in only one version, and it’s the version that people have heard thousands and thousands of times. There is a correct answer to the question, “What is the tempo of that song?” or, “What is the, the right pitch, starting pitch?” You just record them, you compare it to the CD, and you, you look at the pitch and the tempo and you see how close they got.

So, coming back to emotion in music- what are the possible theories about why music affects us emotionally?

There are a lot of different factors that go into our emotional appreciation of music.  Some of it is the memories we have of a particular song, which we heard at a particular time in our lives, or it reminds us of a song that had those qualities. Some of it has to do with just the beat, the pulse. Music like James Brown or March music, for that matter, can be invigorating. It makes you want to move your body. Other music can make you, uh, just sort of melt and relax.  It’s, it’s either composed to have that affect, or it’s performed to have that affect.

We do know that listening to music releases certain neurochemicals. If you listen to music that you enjoy, it releases dopamine, a so-called “feel-good hormone”. It can also release prolactin, the comforting hormone that’s associated with mothers lactating and feeding their infants.

There’s another hormone called oxytocin that’s the so-called “trust hormone.” This is the hormone that’s released when two people- well, if a person has an orgasm, oxytocin is released, and it makes them bond to the person that they’re with. If two people have an orgasm at the same time, they bond to each other. There’s an obvious evolutionary advantage for this. Oxytocin causes feelings of trust with the person. For reasons that we don’t fully understand, when people sing together, oxytocin is released. People trust more, people that they’ve sung and played music with.  So there’s all this neurochemical change that occurs, in response to playing and listening to music.  And we’re just at the beginnings of trying to sort it all out.

Do you think in a very broad sense, that it’s more because we associate music with something that creates an emotion, or because there’s something structural about the nature of music itself?

I think music contains an enormous amount of information. And I mean information in the technical sense of information theory, the amount of unique content.  That there’s more information than speech.  It’s more complex a signal. And so I think that although music doesn’t convey information like, “Hey, would you open the window over there?”, it conveys emotional information that’s very nuanced, and we’re sensitive to that. I think that music was probably an early form of emotional communication between humans, and the reason it lasted even after the introduction of language, is that it’s much better at some forms of communications, in some feelings that you want to communicate, than language is. It’s much better at communicating the dynamics of human emotion.

Oliver Sacks, MD, FRCP: We are wired for speech, we are wired for spoken language, for expressing and understanding spoken language. That’s to say any human being who is exposed to language at a critical stage of development in their second or third year will acquire language without any explicit form of teaching. Comsky above others has spoken wonderfully about this, but basically exposure to language activates language parts of the brain. However we are not wired for written language in the same way. Written language only goes back five or seven thousand years. There is no built-in circuitry in the brain for written language. But a circuitry is developed through learning to write. A circuitry which may be somewhat different in different people. In other words what is already in the brain is recruited and pressed into a new use when one learns to write. So in this way is music like speech? Or is it like writing? I’m inclined to think, but here only one can speculate, that both of these are involved. I think there are certain aspects of music which do not have any equivalent in speech, in particular the pulse of music, the steady rhythm, and its synchronization with movement.  I think there is good reason for supposing for that is built in, and there are anatomical connections, which are strongly and almost exclusively developed in human beings.

Brian Greene: Perhaps the most familiar kind of interval in music is the octave where you have C and another C They sound kind of the same but the second one is higher pitch relative to the first. Mathematically we know how those two waves, those two vibrations relate to one another. So when two notes are an octave apart the wavelength of one is twice the wavelength of the other or said differently the frequency of the higher one is twice the frequency of the lower one. So that is a very simple relationship between how quickly the note, the string if it is producing that note is vibrating, and if it’s vibrating twice as fast, it’ll be an octave higher.

There’s a lot of math in music in that the relationship between vibrations can be phrased mathematically. The art of music of course goes beyond the math in doing things that don’t really come out of a formula, don’t come out of some well defined system of going from one note to the next but using sort of creative genius to do things unexpectedly. That’s where I think the music happens.