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 An Infinite Regression") á la funk bassist Larry Graham and the double thumping technique pioneered by Victor Wooten — as well as harp-like arpeggios. Ihsahn of the black metal band Emperor began playing seven-string guitar in 1999 and first played eight-string guitar on his 2010 album "After". Rusty Cooley tunes his eight-string guitar like a standard six-string expanded in both directions. This tuning offers both deeper bass tones than a conventional guitar and extended range in the higher register for lead melodies. Guitarist Justin Broadrick of the English industrial metal band Godflesh introduced his eight-string playing on the 2014 Godflesh