Before we dive into things lie music notation, chords, scale systems and the likes, we should understand the basic nature of music. When does a tone become a musical tone? The answer: When we perceive a sound as a regular, smooth pitch.

Let me demonstrate:

Below, you can see the waves produced by a slamming door.

Such graphs are seen in many places all the time, but even I had a hard time explaining what it actually shows! There are three things you can read from such a graph:

1. Amplitude: How big is each wave? in the example, amplitude decreases towards the right, indicating that the sound is getting quiter.
2. Frequency: How often does the wave swing? The more “swings”, technically called “nodes”, the higher the pitch.
3. Period: How much real time does one node take to complete?

A physics major will tell you there’s lot more to see here, but we’ll stick to these basics for now. The x-axis is time, while the y-axis is loudness, that’s why the higher a node is plotted on the graph, the louder a sound is. The more nodes per second, the higher the sound. With me here?

In the example of a door slamming, the nodes are irregular, sudden, and thus aren’t perceived as a single tone by our ears and brains. The frequency varies wildly, which doesn’t allow us to catch a certain tone.

Here’s the plucking of a guitar string:

Notice the uniform frequency that hardly changes. The amplitude drops with time, but that is just the fading away of the sound.

One more thing: When a wave goes below the x-axis, it doesn’t become “quieter”, in fact, silence is only existent when the wave touches 0 on the y-axis. If it goes below, it is exactly as loud as when it goes above the x-axis. We’ll explore more of this later.

So now I hope you have a basic understanding of why somethings are called “music” and other’s aren’t. Keep playing!

Post from: The Good Musician