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
Eight-string guitar slew of new age progressive metal and djent artists. Seeking a guitar tuning that would facilitate jazz improvisation, Ralph Patt invented major-thirds tuning in 1963. Patt's tuning is a regular tuning, in the sense that all of the intervals between its successive open strings are major thirds; in contrast, standard guitar tuning has one major-third amid four fourths. Seven-string guitars are needed for major-thirds tuning to have the E-e' range of the standard tuning. Having an eight-string instrument allowed Patt's guitar to have G (equivalently A) as its open note. Patt purchased six-string archtop hollow-body guitars that were then modified