Guitar chord for chords having their root note on the third, fourth, fifth, and sixth strings. For a six-string guitar in standard tuning, it may be necessary to drop or omit one or more tones from the chord; this is typically the root or fifth. The layout of notes on the fretboard in standard tuning often forces guitarists to permute the tonal order of notes in a chord. The playing of conventional chords is simplified by open tunings, which are especially popular in folk, blues guitar and non-Spanish classical guitar (such as English and Russian guitar). For example, the typical twelve-bar blues
Scale length (string instruments) All other things being equal, increasing the scale length of an instrument requires an increase in string tension for a given pitch. A musical string may be divided by the twelfth root of two formula_1, approximately 1.059463094 and the result taken as the string-length position at which the next semitone pitch (fret position) should be placed from the previous fret (or, in case this is the first calculation, the nut or zero fret) of the instrument. This quotient is then divided again by itself to locate the next semitone higher, and so on. Alternatively, the string may be divided by