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
Seven-string guitar A. Seven-string semi-acoustic archtop guitars were used by jazz-guitarist Ralph Patt after he began exploring major-thirds tuning in 1964. 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, the standard guitar-tuning has one major-third amid four fourths. Major-thirds tuning has a smaller scope than standard guitar-tuning, and so Patt started using seven-string guitars, which enabled major-thirds tuning to have the E-e' range of the standard tuning. He first experimented with a wide-neck Mango guitar from the 1920s, which he modified to have seven strings in