There are four primary waveforms that are adopted as the basic ingredients of any respectable sound and can be found throughout audio production; sine wave, square wave, triangle wave, sawtooth wave.
A sine wave is the simplest of all waveforms and contains only a single fundamental frequency and no harmonics.
The sine wave is the simplest waveform
It is the fundamental frequency that determines the pitch of a sound.
Virtually all musical sounds have waves that are infinitely more complex than a simple sine wave. It is the addition of harmonics and overtones to a wave that make it possible to distinguish between different sounds and instruments; the timbre.
The square wave is more complex than a sine wave as it contains additional odd harmonic content. As the name suggests, the envelope of a square wave looks square.
When viewed on a waveform graph, it can be seen that the amplitude instantly changes from its minimum to maximum value. There is no smooth transition as seen in the sine wave.
The triangle wave is comparable to the square wave in that it contains a fundamental sound plus odd harmonics. However, the power of each harmonic in the triangle wave is twice as low as their counterparts in the square wave. Thus, the power of the harmonics in the triangle wave is reduced twice as fast as in the square wave.
The sawtooth wave contains both odd and even harmonics and is said to be the richest in terms of timbre.
The above waveforms are used on analogue synthesizers and digital counterparts to generate various effects using voltage controlled oscillators and filters, for example, a low frequency oscillator (LFO) - more on this in a future article.