Title:	Location	K-4	5-8	9-12	Description	Discipline
Sound Basics Primer	Kitchen	X	X	X	Sound basics.

What is Music?

There are many possible definitions for music and this is a very subjective matter. First we need to consider the difference between music and noise. Some people find the "noise" of the wind blowing through the leaves on trees or the sounds of the rain falling during a thunderstorm to be "music." Some find the sound of their child's cries to be "music to my ears."

Here's a definition: "Music is organized sound." But does music have to be organized by people? Can the forces of Nature "organize" events like rain and wind into sounds that we consider music? I think so, but the answer to this question, ultimately, is up to each of us.

What is Sound?

Sound is a perception created when our minds interpret nerve signals received from our ears and auditory pathways to our brains. Sound travels to our ears through the air in the form of sound waves, which are changes in air pressure. All sound is created by objects vibrating.

What sounds do people organize into music?

There are thousands of different music cultures in the world. Each defines musical sound differently. One culture's pleasant musical sound may well be another culture's unpleasant sound. However, almost all cultures have one thing in common: musical sound is harmonic sound. That is they use sounds for music making that are primarily based on certain mathematical principles, principles that are not found in sounds we consider to be noise.

What is "harmonic" sound?

Harmonic sound is derived from one of the most basic characteristics of vibration: the harmonic series. The harmonic series is a set of high pitches that occurs in any musical sound. That means that any musical sound is really made up of a group of simultaneously sounding frequencies. So when a flute plays a single note, say a middle C, there are really dozens of frequencies that our ear/brain blends together into what we perceive as a single pitch.

There are also certain mathematical principles that occur in harmonic sounds. The set of simultaneously sound pitches (harmonics or partials) have a unique relationship. They are based on whole number ratios. For example, one pitch might vibrate twice as fast as another. These two pitches can be said to have a two-to-one ratio (2:1). One might vibrate 200 times per second, the other 100 times per second.

Of course, it doesn't work out so perfectly in reality, it is more likely that the one pitch vibrates 202.4 times per second, so the second really vibrates 101.2 times per second. However, the relationship of two-to-one is maintained, that's the important thing to remember.

There are several ways. The oldest is to use parts of the body--clapping hands, snapping fingers, or singing. Next came the use of acoustic musical instruments; instruments that don't rely on electronic amplification to create a sound.

Most acoustic instruments have two major parts. The first is called the primary vibrator. The primary vibrator creates sound waves through friction (a violinist draws a bow across strings), plucking (a guitarist strums a guitar), or striking (a drummer beats a drum).

The second part of an acoustic instrument is called a resonator. The resonator takes the sound produced by the primary vibrator and makes it louder. The wooden body of a violin, for example, is its resonator.

Wind instruments, such as the clarinet or flute, and brass instruments, such as the trumpet, are special cases. They produce sound waves directly when air is blown through their mouth pieces. Since the sound waves produced have relatively loud volumes (amplitudes), wind and brass instruments don't need a resonator.

One wind instrument that does use resonance is the human voice. Skilled vocalists--opera singers, in particular--make remarkable use of the cavities in their heads (principally, the sinus cavities) and in their chests to make their voices as loud or louder than any other acoustic instrument. You can demonstrate this yourself by hearing how much louder and resonant your voice is when you yawn while singing a tone. Putting your throat in a yawning position activates the resonant cavities in your throat and chest.