===Range===
Guitars can also be classified according to their range capabilities. Electric guitars have a 4-octave range, while bass guitars have a 3-octave range which is one-octave lower than the electric guitar's range. The range of these guitars may be altered by using guitars with twelve strings. This is commonly known as a doubled six-string guitar, however the second set of string are tuned to an octave higher than the original strings. Therefore, this would add another octave to the guitar's upper range.
==Tuning==