Today's guitar-synthesizers are direct descendants of originals offered in the 1970s by early manufacturers such as Hammond Innovex & Ovation, EMS, Roland Corporation & FujiGen (GR-500 and GR-300), Ludwig, Norlin Music & Maestro, 360 Systems, Ampeg & Hagström, Arp, Electro-Harmonix. Other notable manufacturers include Casio, New England Digital, Terratec/Axon, Starr Labs, Ibanez, Holt Electro Acoustic Research, Zeta Systems, and Yamaha.
In the early days, there were three main types of guitar-synthesizers:
Later, multi-effects type evolved into modeling guitar, and the other two types evolved into current guitar-synthesizers.
And today, there are two main types of guitar-synthesizers:
Both types have advantages and disadvantages.
Though the term "MIDI guitar" is sometimes used as a synonym, MIDI is not the indispensable feature of guitar synthesizers, especially after advances in DSP technology. Software guitar synthesizers without any special pickups have appeared, featuring polyphonic audio recognition (recognizing polyphonic pitches of each string, and possibly distinguish combination of fret positions and strings).
Typical instruments in this category consist of: