The Insanity that is Music, Part.1

When you listen to a track that particularly gets to your emotions, it almost paints a picture, it draws upon past experiences or feelings to create something meaningful, but in the end all you’re really experiencing is a collection of different air pressures that bounce of your ear drums at just the right time.

I should start with some technical aspects, a sound is what we hear when the air around us vibrates at the right frequency (related to the sounds pitch), somewhere between 20 – 20,000 Hz (Cycles per second); and at an appropriate amplitude (related to the volume) for that frequency to be heard, as sounds that are on the edges of our hearing range need to be much louder for us to hear them (See Fletcher Munson Curve).

We’ve come to represent sound visually as a transverse wave, in reality it’s a longitudinal wave, but in order to easily visualize what sound is, we use the transverse.

In this transverse waveform, a sound (or a full music track) can be represented as a series of these up and down lines. Those values above zero (normal air pressure) represent compression, while those below represent expansion (rarefaction).

It starts to get crazy when we think that we can display an entire track like this, because when you really get down to it, that awesome track you love more than anything is just a long, complex series of these lines played very quickly.

The most simple sound we can get comes from a sine wave, which looks like the picture above. It’s a sound at a single frequency, and sounds like this:

When we start adding other sounds at other frequencies, we get something more complex:

Sounds start to get thicker, contain more harmonic overtones and one of the main features in music—they change over time.

Here’s a zoomed out shot of RJD2‘s Smoke and Mirrors track:

And here’s what it looks like when I zoom in on a small area of about 10 ms:

Here’s what it looks like when we go even further, to about 1.6 ms:

And that’s what music is, what it looks like. From this, these fluctuations in air pressure, your brain will paint you a picture of drums, violins, pianos, keyboards, vocals and so much more, all from these tiny little spikes and dips in air pressure.

But…How?….

Well, your brain is one amazing piece of work. I’ve talked previously about the ways we interpret one instrument from another, and its basis is with overtones, the transient (initial burst of sound), and the change over time.

Play an A on the piano, let’s say that A has a frequency of 440 Hz, well you’re not only hearing that 440 Hz but many multiples of it, 880 Hz, 1,320 Hz, 1,760 Hz, and so on; they’re overtones, while the base 440 is the fundamental frequency. Each of these overtones will sound with different strength and change over the duration of the note, all depending on the instrument.

Unconsciously we hear all of these, our brain analyzes each frequency and overtone series and orders them, grouping them together so we can hear the individual instruments. It’s incredible when you think that, while I can tell you that these frequencies are all being played and heard at the same time, the resulting sound still looks like the zoomed in images above, how our brains can decipher that and recognize everything is almost beyond belief.