JBass is a four strings american Fender Custom shop Jazz bass with flatwound strings.
The first Jazz Bass was made in 1960. It was made to accompany Fender's new guitar at the time, the Jazzmaster. The neck on the Jazz Bass were longer and narrower than any of Fender's previous models. This new design was intended to mimic the feel of the stand-up bass. Even the new mid tones that the guitars could produce were made with jazz musicians in mind. The sound of the Fender Jazz Bass has been fundamental in the development of signature sounds in certain musical genres, such as funk, disco, reggae, blues, heavy metal and jazz fusion and is now used in almost any genre.