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)
Scale length (string instruments) maker. Antonio De Torres (1817–1892) used a scale length of 25.6 in (650 mm), and later makers have followed suit. However, from the mid- 20th Century luthiers seeking increased volume have moved to a 26 in (660mm) scale, which is now the standard for such leading makers as Ramirez. Unlike Stradivarius, Torres had no strong tradition on which to build regarding scale length, so the 25.6 in figure can be attributed to him with confidence. The steel-string acoustic guitar typically has a scale slightly shorter than the classical instrument, the most common scales ranging between "short scale" : 24 inches