http://sequencer.de/synth/index.php/Synthesizer_History_Timeline

This site is fantastic and ranges from.

"1837 - C.G. Page (Salem. Mass) - first to produce electronically generated sound (not necessarily associated with a musical instrument). After inventing the Volta in 1800 (an early battery), in 1837 Page was doing experiments with coils and realized when certain coils were attached to a batter they omitted a ringing sound. While he initially thought the ring came from the electrical current was interrupted (battery disconnected), what was actually taking place was the induction through the coils was causing them to vibrate. via Peter Grenader"

to

"2912 - KalQuestoTron - the first genetically engineered synth. Each cell is an oscillator, filter, and neural sequencer. Can be delivered via injection to always play 'hold music' in your head."