The JS4, also referred to as the Electric Rainbow, is a JS series solid body electric guitar model introduced by Ibanez in 1992. It is a signature model of American guitarist Joe Satriani. It was made in Japan by FujiGen.
The JS4 features a custom painted finish by Satriani's sister, Joan. Each JS4 was hand painted by Joan Satriani, therefore each is a unique creation.
The guitar model itself is based on the JS1. It has an American basswood body bolted to a maple neck with a 22-fret rosewood fingerboard with pearl dot position markers. Components include a pair of DiMarzio humbucking pickups mounted in metal pickup rings, a Lo-Pro Edge double locking tremolo bridge and Gotoh tuning machines.
The JS3 and JS5 are other Satriani models with graphic finishes designed by Donnie Hunt and Carol Satriani, respectively.