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
Guitar chord chord is lowered by an octave. Drop-two chords are used for sevenths chords besides the major-minor seventh with dominant function, which are discussed in the section on intermediate chords, below. Drop-two chords are used particularly in jazz guitar. Drop-two second-inversions are examples of openly voiced chords, which are typical of standard tuning and other popular guitar-tunings. "Alternatively voiced" seventh chords are commonly played with standard tuning. A list of fret-number configurations for some common chords follows: Already in basic guitar-playing, inversion is important for sevenths chords in standard tuning. It is also important for playing major chords. In standard tuning,