Skip to main content

Of Neuroscience and Jazz

I am neither a neuroscientist nor a very accomplished musician, but I'd like to talk about the intersection of neuroscience and music. I have a theory that there is a neuroscience basis for why it takes a mature musical palate to enjoy jazz.

First, let me say a little something about neuroscience (based on the limited understanding I've gained by watching a bunch of talks). One of the things your brain is particularly good at is recognizing patterns and predicting patterns. At the lowest level, if two nerves are close to each other, and they both fire, it's counted as a pattern--i.e. those two things are connected. Similarly, if a nerve fires and then a short while later it fires again, that's a pattern as well. Hence, if both of my fingers feel something, there's a pattern, or if I feel a tapping on a single finger, that's a pattern as well.

However, the brain is not limited to low level patterns. Rather, it can respond to a hierarchy of patterns. Paraphrasing Pavlov, if a dog hears a can opener and then smells food and then gets fed, we all know that the dog will soon recognize the pattern and start salivating as soon as he merely hears the can opener. My point is that a sophisticated pattern is composed of lower level patterns recursively, all the way down to the level of individual neurons firing.

Next, let me talk about sine waves and chords. Let's start with a single note. A single note might look something like y = sin(x):This wave is very simple, and somewhat boring.

(By the way, I'm using to create these graphs. WolframAlpha is really interesting. It's a computational knowledge engine, and graphing things is just one of a ton of things it can do.)

Now, let's look at a chord consisting of a single note as well as the note that is an octave above it. Here's y = sin(x) + sin(2 * x):This curve is somewhat more sophisticated. However, you can still recognize the pattern by the time x = 10.

Now, let's look at what I think is a fifth, which is still a nice sounding chord. Here's y = sin(x) + sin(1.5 * x):This pattern is slightly more sophisticated, but it's still pleasingly recognizable.

Now, let me show you something that is not pleasing to the ear. This curve represents what might happen if you hit two keys that are right next to each other on the keyboard. Here's y = sin(x) + sin(1.1 * x):This curve pulses in an ugly way. You have to get all the way out to x = 120 or so to even see the pattern. In a manner of speaking, the pattern is only there by "brute force".

So what's my point? Simple patterns are easy to recognize, and they can be recognized in less time (i.e. for smaller variations of x, which I probably should have called t).

Here's something that I think is more of a jazz chord. Here's y = sin(x) + sin(1.25 * x) + sin(1.5 * x) + sin(2 * x):This curve is really interesting. You can recognize what's going on by the time you get to x = 50, but the "texture" of the curve is a lot more interesting. Whenever I play this sort of chord, it sounds deep, rich, and interesting. If the first chord reminds me of "Mary had a Little Lamb", this last chord reminds me of the forbidden love between Lancelot and Guinevere and the pain it caused King Aurthur.

So what's my point? You have to go higher up the pattern recognition pyramid in order to recognize more sophisticated patterns. A more sophisticated musical palate is able to recognize patterns that a simpler musical palate may not recognize. That's why jazz requires a sophisticated palate--it uses chords that require more effort to recognize.

Of course, there are many dimensions to music, and individual chords are just one dimension. There are also chord progressions and beats. The same sort of thing applies to these other dimensions.

Here's the circle of fifths (thanks Wikipedia!):Pick any three chords in a row on the circle of fiths, such as C, G, and D, and you have the basis for a simple, feel-good song. If you just bounce around between the different chords on a guitar using different strumming patterns, you'll immediately recognize a song you already know or create a new song that sounds pleasing. Throw in a few 7th chords and a few minor chords, and the song starts taking on additional richness because the pattern becomes less simple.

If you try to use more than three chords from the circle of fifths, your brain might be left thinking, "Wait a minute. What key am I supposed to be in?" It may be more difficult to recognize the pattern. However, this is exactly the sort of thing that happens in jazz.

The same thing applies to beats. Here's a simple walz, "Um pa pa. Um pa pa." Here's a typical rap beat, "Bum chbum bum chbumbum ch bum bum ch." More sophisticated beats require more sophisticated pattern recognition.

Every song is composed of some pattern repetition and some pattern violation. Simple, pop songs that are enjoyable by youthful palates involve a lot of pattern repetition and less pattern violation. Sophisticated music palates enjoy songs with less pattern repetition and more pattern variation. Furthermore sophisticated music palates get bored of songs more quickly. They recognize the patterns quickly, and they're ready to move on.

Furthermore, popular songs are played more often on the radio so that your brain has a better chance to become more familiar with the patterns. A listener will usually enjoy the song more after listening to it 10 times than if he's only listened to it once. If a song has so much pattern repetition that you enjoy it the first time, you'll often grow bored of it very quickly. Conversely, it's very difficult to enjoy sophisticated classical pieces the first time you hear them. All the popular classical pieces have been driven into our heads since we were kids.

Why is this? I think this can be explained by neuroscience as well. The brain works hard to find patterns, and when it does, the simple recognition of a pattern is somewhat calming. It's says something like, "Hmm, I've seen that pattern before. Coooooool." However, if a pattern is repeated too often, the brain starts to filter it out; it becomes boring. It says, "Nothing new here. Pay attention to something else." Pattern violations catch your attention. You brain says, "Hey, wait a second. I didn't expect that! You should pay attention because something new is happening!" Hence, composers must always straddle the line between calming pattern repetitions and exciting pattern violations. How far you go in either direction dictates how sophisticated a musical palate will be required to enjoy the song, and thus, who will enjoy it.

Ok, so that's my theory of neuroscience and music. I don't have any MRIs to back it up, nor do I have the educational background to claim real expertise on the subject. Nonetheless, I think there's some truth to it.


muayguy said…
I have my own strong feelings about(against) jazz music. I like it as a "spice", but if I have to eat it without any dressing I'm gonna puke. That being said,... I've studied music composition/orchestral conduction for 5 years and all of this seems pretty accurate. I was skeptical about the article since this is mostly a programming related blog but everything sounds great. There's actually a academic music movement you might want to "check" called the spectralism. In spectral music, the composers try to "mimic" the sound spectra of a small "chunk" of music (could be 1 bar of a choral work by Bach, could be the attack of a trumpet on a note) with their own orchestrations. Very colorful indeed. And then... regarding the patterns, there's another movement called "the new complexity", which the patterns are well...complex. So complex that even an averagely well trained musician cannot recognize them. TNC, I don't really like it very much, but spectral music is quite enjoyable, check Grisey's "Partiels" for a text-book example of this (
jjinux said…
> Filipovic

Great comment. Thanks!
jjinux said…
I don't claim to have a very well developed ear, but listening to Grisey's Partiels was certainly interesting.
Sam Rushing said…
You might enjoy an episode of "Ingenious Minds" on the Science Channel. A guy suffers head trauma and turns into an 'acquired savant' - he becomes obsessed with music and turns into a musical prodigy.
jjinux said…
Thanks! Sounds good!

Popular posts from this blog

Ubuntu 20.04 on a 2015 15" MacBook Pro

I decided to give Ubuntu 20.04 a try on my 2015 15" MacBook Pro. I didn't actually install it; I just live booted from a USB thumb drive which was enough to try out everything I wanted. In summary, it's not perfect, and issues with my camera would prevent me from switching, but given the right hardware, I think it's a really viable option. The first thing I wanted to try was what would happen if I plugged in a non-HiDPI screen given that my laptop has a HiDPI screen. Without sub-pixel scaling, whatever scale rate I picked for one screen would apply to the other. However, once I turned on sub-pixel scaling, I was able to pick different scale rates for the internal and external displays. That looked ok. I tried plugging in and unplugging multiple times, and it didn't crash. I doubt it'd work with my Thunderbolt display at work, but it worked fine for my HDMI displays at home. I even plugged it into my TV, and it stuck to the 100% scaling I picked for the othe

ERNOS: Erlang Networked Operating System

I've been reading Dreaming in Code lately, and I really like it. If you're not a dreamer, you may safely skip the rest of this post ;) In Chapter 10, "Engineers and Artists", Alan Kay, John Backus, and Jaron Lanier really got me thinking. I've also been thinking a lot about Minix 3 , Erlang , and the original Lisp machine . The ideas are beginning to synthesize into something cohesive--more than just the sum of their parts. Now, I'm sure that many of these ideas have already been envisioned within , LLVM , Microsoft's Singularity project, or in some other place that I haven't managed to discover or fully read, but I'm going to blog them anyway. Rather than wax philosophical, let me just dump out some ideas: Start with Minix 3. It's a new microkernel, and it's meant for real use, unlike the original Minix. "This new OS is extremely small, with the part that runs in kernel mode under 4000 lines of executable code.&quo

Haskell or Erlang?

I've coded in both Erlang and Haskell. Erlang is practical, efficient, and useful. It's got a wonderful niche in the distributed world, and it has some real success stories such as CouchDB and Haskell is elegant and beautiful. It's been successful in various programming language competitions. I have some experience in both, but I'm thinking it's time to really commit to learning one of them on a professional level. They both have good books out now, and it's probably time I read one of those books cover to cover. My question is which? Back in 2000, Perl had established a real niche for systems administration, CGI, and text processing. The syntax wasn't exactly beautiful (unless you're into that sort of thing), but it was popular and mature. Python hadn't really become popular, nor did it really have a strong niche (at least as far as I could see). I went with Python because of its elegance, but since then, I've coded both p