Seven-string guitar string is augmented with a high octave string. Many of McGuinn's notable guitar solos utilize the G string of the twelve-string guitar to perform the main melody, and therefore the Martin seven-string guitar was designed to achieve this extended range playing without the need for doubling all six of the guitar's strings. In 2010, Inox Guitars has created a mix of the Brazilian Viola caipira and the Russian semistrunka (семиструнка). This instrument has 2 bass strings (as the 6th and 7th strings of the semistrunka) and five treble courses (as the Viola caipira) and it is used in open tuning
Zero fret continue perpetually. Some manufacturers that frequently use(d) a zero fret are Gretsch, Kay, Selmer, Höfner, Mosrite, Framus, Vox, Vigier and bass guitar manufacturer MTD. Now very few manufacturers use this design and those who do list it as a feature. Steinberger uses a zero fret with their headless guitars but omit the nut; strings are mounted in place where the head would normally be, so there is no need for the string guides that the nut provides. 2015 model year Gibson guitars incorporate a zero fret in order to accommodate a brass adjustable nut, which the manufacturer claims causes better