Unlike the piano, the guitar has the same notes on different strings. Consequently, guitar players often double notes in chord, so increasing the volume of sound. Doubled notes also changes the chordal timbre: Having different "string widths, tensions and tunings, the doubled notes reinforce each other, like the doubled strings of a twelve-string guitar add chorusing and depth". Notes can be doubled at identical pitches or in different octaves. For triadic chords, doubling the third interval, which is either a major third or a minor third, clarifies whether the chord is major or minor.
Left-handed players sometimes choose an opposite-handed (mirror) instrument, although some play in a standard-handed manner, others play a standard-handed guitar reversed, and still others (for example Jimi Hendrix) played a standard-handed guitar strung in reverse. This last configuration differs from a true opposite handed guitar in that the saddle is normally angled in such a way that the bass strings are slightly longer than the treble strings to improve intonation. Reversing the strings, therefore, reverses the relative orientation of the saddle, adversely affecting intonation, although in Hendrix's case, this is believed to have been an important element in his unique sound.