Standard tuning strings. This is done to simplify fingering. A few guitarists, mostly those using tapping, play without this interval, instead tuning in all fourths; thus on a six-string guitar the top two strings become C and F instead of B and E. Other unusual tunings include all major thirds, all minor thirds, and various other choices. In standard notation, the guitar sounds one octave lower than it is written. This is to avoid switching between treble and bass clef, or using ledger lines or 8vb, since it is very common to play past the 12th fret on the E string (E)
Acoustic bass guitar are quite rare. Like the traditional electric bass and the double bass, the acoustic bass guitar commonly has four strings, which are normally tuned E-A-D-G, an octave below the lowest four strings of the 6-string guitar. Like the electric bass guitar, models with five or more strings have been produced, although these are less common. In part, this is because the body of an acoustic bass guitar is too small to produce a resonance of acceptable volume at lower pitches on the low "B" string. One solution uses the five string acoustic bass to add an additional high string ("E-A-D-G-C")