The seven-string guitar adds one additional string to the more common six-string guitar, commonly used to extend the bass range or also to extend the treble range.
A Brazilian seven-string guitar
Soulezza 7 String Guitar
"The Guitar Player" by V.A. Tropinin (1823)
Seven-string electric guitar Ibanez RG7321BK
The guitar is a stringed musical instrument that is usually fretted and typically has six or twelve strings. It is usually held flat against the player's body and played by strumming or plucking the strings with the dominant hand, while simultaneously pressing selected strings against frets with the fingers of the opposite hand. A guitar pick may also be used to strike the strings. The sound of the guitar is projected either acoustically, by means of a resonant hollow chamber on the guitar, or amplified by an electronic pickup and an amplifier.
Instrument labeled "cythara" in the Stuttgart Psalter, a Carolingian psalter from 9th century Paris.
19th-century guitar made by luthier Manuel de Soto held by Spanish guitarist Rafael Serrallet
Guitar collection in Museu de la Música de Barcelona
The Guitar Player (c. 1672), by Johannes Vermeer