8-string guitar

An eight-string guitar is a guitar with two more strings than the usual six, or one more than the Russian guitar's seven. Eight-string guitars are less common than six and seven string guitars, but they are used by a few classical, jazz, and metal guitarists. However, eight strings is the standard for lap steel and pedal steel guitars. The eight-string guitar allows a wider range, or non-standard tunings (such as major-thirds tuning), or both.

Various non-standard guitars were made in the 19th century, including eight-string guitars played by Italians Giulio Regondi and Luigi Legnani.

In the 1940s, American lap steel guitars generally standardized with eight strings. Tuning was usually based on either the E9 chord for "Nashville" style or the C6 chord for jazz configurations. Recently, eight-string guitars have become very popular throughout Heavy Metal and its surrounding subcultures and subgenres. Many believe this wave of eight-string guitars were inspired almost exclusively (at the initial point) by Swedish Progressive Death Metal band Meshuggah. Other modern artists helping to bring the eight-string into the light include Progressive Metal band Animals As Leaders, Progressive Metal band After The Burial, Dino Cazares of Fear Factory (He played a Ibanez LACS eight-string in his band Asesino c. 2005), Per Nilsson of Scar Symmetry, as well as a slew of new age Progressive Metal or "djent" artists.

Seeking a guitar tuning that would facilitate jazz improvisation, Ralph Patt invented major-thirds tuning in 1963. 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, standard guitar tuning has one major-third amid four fourths.

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