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
Scale length (string instruments) electric basses built in the 1930s by fitting an otherwise normal double bass with electric pickups, and so had a scale length of about 43" (109 cm). In 1951 the Fender Precision Bass shortened this to 34" (86 cm). This is still often regarded as the standard length for a bass guitar. On a modern bass guitar, 30" (76 cm) or less is considered "short" scale, "standard" (also called "long") scale is 34" (86 cm) for a 4-string and 35" (89 cm) for a B-E-A-D-G 5-string, and "extra-long" scale basses of 36" (91 cm) also exist. Quite an uncommon scale