fretless bass
While electric bass guitars are traditionally fretted instruments, fretless basses are used by some players to achieve different tones. Rolling Stones bassist Bill Wyman is sometimes identified as the first to make a fretless bass. In 1961, he converted a used UK-built Dallas Tuxedo bass by removing the frets and filling in the slots with wood putty. Wyman used it to record songs such as "Paint It, Black" and "Mother's Little Helper" in 1966.
In 1966, Ampeg introduced the AUB-1, the first production fretless bass. Fender followed with a fretless Precision Bass in 1970. Some fretless basses have "fret line" markers inlaid in the fingerboard as a guide, while others only use guide marks on the side of the neck. In the early 1970s, fusion-jazz bassist Jaco Pastorius coated the fingerboard of his de-fretted Fender Jazz Bass in epoxy resin, allowing him to use roundwound strings for a brighter sound without damaging the fretboard.
See also: fretless guitar