A player can use the fretting hand to change a sounded note, either by fully muting it after plucking it, or by partially muting it near the bridge to reduce volume, or make the note fade faster. The fretting hand often mutes strings that are not being played to stop sympathetic vibrations, particularly when the player wants a "dry" or "focused" sound. On the other hand, the sympathetic resonance of harmonically related strings are sometimes desirable. In these cases, a bassist can fret harmonically related notes. For example, while fretting a sustained "F" (on the third fret of the "D" string), underneath an F major chord being played by a piano player, a bassist might hold down the "C" and low "F" below this note so their harmonics sound sympathetically.
Extended-range basses (ERBs) are basses with six to twelve strings—with the additional strings used for range rather than unison or octave pairs. A seven-string bass (B0–E1–A1–D2–G2–C3–F3) was built by luthier Michael Tobias in 1987. This instrument, commissioned by bassist Garry Goodman, was an early example of a bass with more than six single course strings. In 1999 South American ERB player Igor Saavedra designed one of the first eight-string ERBs known, and asked Luthier Alfonso Iturra to build it for him.  Conklin builds custom ERB basses. The Guitarbass is a ten-string instrument with four bass strings (tuned E–A–D–G) and six guitar strings (tuned E–A–D–G–B–E). Luthier Michael Adler built the first eleven-string bass in 2004 and completed the first single-course 12-string bass in 2005. Adler's 11- and 12-string instruments have the same range as a grand piano. Subcontrabasses, such as C♯–F♯–B–E (the lowest string, C♯0 being at 17.32 Hz at around the limit of human hearing) have been created. Ibanez had released SR7VIISC in 2009, featuring a 30-inch (762 mm) scale and narrower width, and tuned as B–E–A–D–G–C–E; the company dubbed it a cross between bass and guitar.[better source needed]
The bass guitars will have either 4, 5 or 6 strings. Though it may be tempting to go for the guitar with 6 strings, going for the 4-stringed is good for a new player. A bass guitar is a type of stringed instrument that plays a lower tone and sounds more impressive than a regular guitar. The most notable difference is that a bass guitar may have as few as four strings and they are much thicker. The thicker strings are what give the bass its low tone.