[A6] What is fat anyway?

[Jon Cooper]

In a sound design context, an organic sound is so called because it contains elements within that evolve without being predetermined by its programmer, noise modulation aside this is the purest way it can be explained, the term organic can also be applied to the way in which a musician sequences (plays) the audible notes as it is the human element that is looked upon as organic, the word organic being used loosely to describe something that resembles the signature of something living / created by a living organism.

The term "fat" applies to the texture / richness of the sound and can apply to almost all types of audible signal as it is largely the harmonic content that dictates the perceived fatness of a sound source. 

Often due to the purity the unbroken waveform produced by an analogue oscillation analogue synths can sound naturally richer to the ear or in my own terminology I would describe their sound  as more solid sounding. Other than the obligatory bass line I would describe rich pads and glassy string / atmospheric sounds as fat sounding so in my interpretation sounds containing frequencies from the entire audible spectrum can be perceived as fat, or should that be "PHATT".