alt Hacker News> Electric guitars attack hard, decay fast, and don’t sustain like bowed strings or organs.
Since the 1980s, we have had the "Sustainiac": an active circuit installed in the electric guitar along with a "reverse pickup" which is energized in order to excite vibration in the strings.
With this device, at the flip of a switch, you get indefinite sustain on any note on the neck, at any volume, distortion or not --- even if the electric guitar is not plugged into an amplifier at all, and just heard acoustically.
The best implementations of this have a three way harmonic switch. You can choose between excite the fretted (or open) note itself (fundamenta a.k.a first harmonic), an octave above it (second harmonic) or a higher harmonic still.
You can be sustaning the given note, and then at the flip of a switch, it will fade over to the higher harmonic.
YouTube videos of this in action are worth checking out.
Here is one:
If you don't want to or can't install a Sustainiac pickup, you can get a much cheaper handheld one-string "E-Bow" that does the same thing. It's not as easy to use as a Sustainiac and you can't also be playing with the whammy bar unlike with a Sustainiac, but you can get it to do tricks a Sustainiac can't do: see the "spiccato" section in https://www.youtube.com/watch?v=b0V3pzxma-8
I've also managed to make an E-Bow work with a steel-string acoustic guitar (but only on one string IIRC).