The art of making music is arguably one of the oldest forms of creative work humanity has. It’s easy to imagine early humans clapping hands and banging rocks to a rudimentary rhythm as a friend in the neighbouring cave decorated their walls with images from the latest hunt. Because of the unique way our brains have evolved to process the sounds, we know that we’ve been making music for a long time. Music, unlike when we process normal background sounds or even human speech, is a whole brain activity.

The science of music is a relatively new and gigantic field of scientific study. We can only hope to scratch the surface here, but scratch it, we will!

Let’s look at some of the fundamental aspects of the science of music and sound.

The Science of Music

Traveling Waves

As you likely learned in school, all sounds move in waves. You might be tempted to think about these waves like ripples on a pond. That’s not a bad metaphor, but it’s not the most accurate description of a sound wave. Rather than move up and down like the waves on a lake, sound waves are more like alternating waves of high and low pressure pushing outward from their source in all directions. The more significant the difference between the high- and low-pressure layers, the louder the sound volume.

Also, unlike liquid waves confined to the pond, sound waves can travel through almost anything they encounter. That includes your body, which is why you can feel the vibrations if you’re close enough to the speakers.

Pitch

Would you be surprised to learn that pitch is also determined by those pressure waves? In fact, the science of music tell us that pitch is determined by thickness of each wave:

• High-pitched sounds are extremely thin and rapid. A high note will produce thousands of short waves, maybe eight to ten inches thick, every second.
• On the other hand, a low note might produce only about 60-65 waves per second, but each wave could be up to 17 feet thick.

And if you’re still standing close to that speaker, you’ll be able to feel the differences in pitch as the wave thicknesses pass through your body. You spend a relatively longer time inside the waves of a low note, feeling the changes. On the other hand, the waves of higher notes travel through your body just as well, but they vibrate so quickly between the high and low pressures that you’re not likely to feel the changes.

What’s really interesting about this is that the sound you hear doesn’t exist outside your brain! It’s like that old question: “If a tree falls in the forest and no one is around to hear it, does it make a noise?” The answer is, in fact, no! Without an ear and all its intricate inner workings to translate those alternating waves of high and low pressure into something our brains perceive as a sound, they remain nothing more than pressure waves. Your brain literally turns them into sound and music!

Volume

An interesting quirk of sound and how we perceive it exists in the concept of volume. Have you ever noticed that ten violins only sound about twice as loud as a single violin? There are two reasons for this. The first is our ears: evolution has ensured that we hear quiet noises (like that of a predator stalking us) clearly, and any increase in volume has less impact. The second reason is that when people play the same instrument together, some sound waves cancel each other out. The violins don’t play precisely simultaneously, leading to their sound waves colliding in the air, reducing the overall volume.

Interestingly, our ears are much more sensitive to higher-pitched sounds. That might be because animal calls are often high-pitched, which would have warned our ancestors of nearby danger. Whatever the evolutionary reason for it, when it comes to music, it means that in order to get a balanced sound between a lower bass instrument, like a bassoon, and a high-pitched instrument, like a clarinet, the bassoonist will have to play as loud as he or she can.

Another oddity of volume is regarding the length of a note or sound. For whatever reason, the longer a note is held, especially for longer than 20 or 30 seconds, the more its volume seems to fade. It’s not really fading; your brain stops noticing it as much, allowing it to fade into the background of your perception as your ears listen for something new.

What Makes Music Different From Noise?

Everything that creates a sound does so in this manner. So, what makes music different from all other sounds? The science of music has more tricks up its sleeve; the mechanical aspects of how your brain collects sounds differs from how it processes them. Your brain always looks for patterns, and listening to sounds is no different. Musical notes are differentiated from everything else by our brains because music consists of ripples of regularly repeating patterns. Everything else is just chaos.

It’s these patterns that engage your brain when you hear music. Once your brain identifies a pattern in the sounds it’s hearing, it tries to predict what will come next. But music isn’t always predictable, which keeps your brain guessing and stimulates and surprises you with the outcomes of those predictions.

A Musical Misconception

These patterns are what make music exciting to us. They’re what get our toes tapping. But they have also led to one of the biggest and most widely held incorrect beliefs about music: that your heart rate speeds up or slows down to try to match the music you’re listening to. This idea likely came from the fact that the ranges of human pulse rates and musical rhythms overlap. Generally speaking, the tempo of most music is between 40 and 160 beats per minute (bpm), and most human pulse rates range from about 60 bpm for someone at rest to about 150 bpm for a healthy adult exercising.

The energy and excitement of the music and your dance moves raise your heartbeat, not the act of listening. But does that matter? Just enjoy the feeling and get yourself out on the dance floor!

Looking to start your own study of the science of music? Check out all The Music Studio’s programs, including Music Theory, and sign up today!