Guitar It is flat on classical guitars and slightly curved crosswise on acoustic and electric guitars. The curvature of the fretboard is measured by the fretboard radius, which is the radius of a hypothetical circle of which the fretboard's surface constitutes a segment. The smaller the fretboard radius, the more noticeably curved the fretboard is. Most modern guitars feature a 12" neck radius, while older guitars from the 1960s and 1970s usually feature a 6-8" neck radius. Pinching a string against a fret on fretboard effectively shortens the vibrating length of the string, producing a higher pitch. Fretboards are most commonly
Nine-string guitar 25.5"). Tuning the highest string to an A4 or higher can be accomplished with a shorter scale length and/or a thinner string such as a .008 or .007. Extended range nine-string guitars also sometimes have a multi-scale fingerboard design where the bass strings will be longer than the treble strings, which helps with proper intonation of the lower strings, improves string tension balance across the strings, improves harmonic overtones, overtone series, and inharmonicity. Notable guitar players of double-stringed nine-string guitars: Notable guitar players of extended-range nine-string guitars: Nine-string guitar A nine-string guitar is a guitar with nine strings instead of