I knew every note of [Karn Evil 9] and could hear the sweeping filters and the fundamental wave shapes underneath ... scope in the form of a Fast Fourier Transform (FFT). For this demonstration ...

The representation of a PERIODIC sound or WAVEFORM as a sum of Fourier components (i.e. pure SINUSOIDAL WAVEs). According to the FOURIER THEOREM, periodic sound may be shown to consist of SINE WAVEs ...