The synth guitar, though it has been around for a long time, has never really caught on, though each new iteration is held up as the instrument that will finally break through. My "vintage" synth has tracking problems that still exist in the latest instruments, and which require a rather different striking and fingering technique than either acoustic or electric guitar--

Mr. Campin has indicated that the synth pipes require different finger techniques as well, so the future of these instruments is far from certain.