Synth players have studied and emulated timbres (and created new ones) since the pipe organ (an additive synthesizer). Many books have been written about timbre

Synth players have studied and emulated timbres (and created new ones) since the pipe organ (an additive synthesizer). Many books have been written about timbre in electronic terms -- a combination of frequencies and amplitude envelopes that either sound to our ears like classical instruments, or like something else entirely. I would go so far as to say understanding and selection of timbre is 50% of the work of a synth player.