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
Rhythm game accessories existing "Rock Band 2" drum sets. For the pro guitar mode of "Rock Band 3", a pro guitar controller is required. Unlike standard guitar controllers, pro guitars allow input of any fret/string combination, allowing accurate simulation of a real guitar. The Fender Mustang Pro Guitar controller, which is based on the Fender Mustang, has 102 buttons along its neck which simulate holding the guitar strings against the fretboard. All six strings are represented along 17 different frets. In order to simulate picking/strumming, the Mustang pro controller features a "string box" located on the body of the controller (around the position