Introduction

Sounds

Sound is a vibration of an object, which travels through the air to our ear (or to a microphone), which detects that sound. Vibrations could be created in many ways: hitting a taut string, a drum, a drinking glass, clapping hands, a running car engine, a vibrating speaker of our TV, etc.

Tones

When an object vibrates in a regular pattern (e.g., a taut string, which goes there and back many times per second), we call that sound a musical tone. A number of vibrations per second is called a frequency or a pitch and is measured in hertz (1 hertz = 1 vibration per second).

Try to play a tone of different frequencies. What are the lowest and the highest frequencies that you are able to hear? Many speakers can not play low frequencies below 120 Hz, also called bass.

The opposite of tones is the sound with no regular patterns. With no patterns, vibrations seem to be random, and we call it noise. Below, you can see a random sound pattern, which will be played by your device.

Timbre

A musical tone has a clear pattern, which repeats many times per second. The shape of that pattern is called timbre. Many instruments can play a tone of 220 Hz, but with a different timbre. A timbre of a violin is different than a timbre of a piano. Two people can sing the same vowel "oooo" at the same pitch, but each voice usually has a unique timbre. Even a type of wood could slightly change the timbre of a piano.

If there are two sounds of the same pitch, they sound nice together, no matter what their timbre is. In music, we care only about the pitch. The instrument that you decide to use, or the style of your singing, is totally up to you, as long as you can keep the required pitch.

Try to play a tone of various pitch, and with several predefined timbres. Note that when the pattern has sharp edges, it "sounds sharp". Can you hear it?