Russian guitar usually differs from the wood in the rest of the neck. The neck joint or heel is the point at which the neck is attached to the body of the guitar. The fingerboard is made of hardwood (ebony or rosewood are common), fitted with metal frets of brass or steel. Fret spacing almost always follows the western twelve tone equal temperament (12-tet) system. The surface of the fingerboard may be flat or curved slightly ("radiused"), although the curve on the Russian guitar is usually somewhat less than that of an equivalent western 6-string guitar. Inlayed position markers are common, and
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