Changes

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 There also exist seven and eight (although the second set of strings latter are tuned to an octave higher than the original strings. Therefore, this would add another octave to not common) stringed guitars which usually extend the guitar's upper bass range.