Guild introduced their first bass, the Jet Star, in 1964. It was never a big commercial success, at least not compared to later models. In 1970, the JS-I and JS-II were introduced to replace it; despite some similar details (mahogany body and neck, short 30” scale), the new design was quite a different beast. The body was reshaped to mimic the Gibson EB-0 and EB-3, and after a brief flirtation with Hagstrom-built pickups, Guild installed their own humbucking units. The numeral in the model name indicated the number of pickups, but relatively few JS-Is were built. The price was significantly lower than Gibson, so that even a dual-pickup JS-II cost less than a single-pickup EB-0. By 1971, Guild had begun installing tone switches on both models that allowed the neck pickup to produce range of sounds on its own.

This particular JS-I is unusual in a couple of respects. The emerald green finish was a custom option at the time, but it was rarely ordered in the 1970s and is extremely rare on a solidbody bass. The body is actually maple rather than the usual mahogany, which was probably done for aesthetic reasons – it prevents the already dark finish from looking even darker. This particular bass has been fitted with a couple of non-original bridges (it currently sports a reissue bridge) and the wiring has been completely re-done, though to the original schematic. The pickup is original, but the maple body gives the bass a slightly brighter voice than its mahogany counterparts.