Patterns of sound
Patterns play an important role in music. The sounds we hear and recognize as music always have patterns you can pick out. Musical sounds follow harmonic patterns, blending and weaving together to please the ear. Even true “noise” which has little inherent harmonic pattern (like, for example, a cymbal crash) is musical in context of a song, espcially when it is applied in some rhythmic pattern.
A musical tone is a sound wave with a repeating pattern, a pulsing wave vibrating through the air at a (relatively) fixed frequency. Musical instruments generate tones or groups of tones. Let’s dig a bit into musical tones and look at how patterns apply to them, and try to understand what their attributes are.
Tones: Parts and Behavior
A musical tone is a pattern of pressure waves in the air and has three characteristics: pitch, volume and timbre. Let’s talk about each.
As the waves hit your eardrums, the vibrations are transmitted to your brain and you hear the tone. If we were to draw a simple tone, it might look a bit like this.
See the nice regular waves moving in a regular pattern? Here’s another tone.
You can see the same nice regular wave pattern, but there are more waves in the same amount of space. The second wave has a higher frequency. If the waves are shorter and scrunched together more closely, the tone has a higher pitch. Frequency = pitch.
So a musical tone has a pitch/frequency which defines it’s highness or lowness on the scale (more on scales later.) Tones with low frequency have low pitch and the reverse is true for high frequency tones.
Musical tones also have volume or amplitude which is a measure of how loud they are. Does that matter to the music beyond your room-mates yelling “turn that stuff down?” Sure does! You can convey a lot of musical interest just by changing the volume/amplitude of the note you’re playing. Here’s an example:
So there you see you can actually start writing music and only play a single note. Just alter the volume!
The final element of our musical tone is tone color or timbre (rhymes with “amber”.) The timbre of any given instrument is mostly unique to that instrument. It’s the reason that flutes sounds like flutes and guitars sound like guitars. You can have the same pitch being played by three different instruments, and still be able to tell them apart.
Here’s an example of a series of tones being played with identical pitch and amplitude, but with a change to the timbre over time. You’ve heard this type of change many times in popular music.
Finally we come to sounds without a regular pattern, sort of a special case. Sound without a regular frequency is called noise. If you hear a random selection of waves that combines many unrelated frequencies it sounds like static, but even static can be musical if a pattern is applied to it!
So the parts of a musical tone are:
- Pitch
- Volume
- Timbre
And noise is sound that combines many unrelated frequencies all jumbled together. (There are many types of noise, which we’ll cover later.)
In the next installment on Music Theory, we’ll talk about pitch, frequencies, scales and how we (in western culture) have been trained to find certain combinations of pitches pleasing and certain ones unpleasant.
Remember, you can do a lot with a single pitch if you just fiddle around with timbre and volume. Here’s an example.
See you next time!
