The four basic wave shapes in synthesis are the sine wave, the triangle wave, the square wave, and the sawtooth wave. These wave shapes are also different variants of the harmonic spectra that help to illustrate the different harmonic structures of sound and how they affect tone color. These different ideological wave shapes also are the cornerstones for analyzing spectral characteristics of natural sound. This lesson helps one to understand how to shape these sound waves using digital audio software such as Pure Data. This episode covers the math involve in shaping these waveforms in pd.