Classification String instrument (plucked, nylon stringed guitars usually played with fingerpicking, and steel-, etc. usually with a pick.) Playing range (a regularly tuned guitar) Related instruments Bowed and plucked string instruments The guitar is a musical instrument with ancient roots that is used in a wide variety of musical styles. It typically has six strings, but four, seven, eight, ten, and twelve string guitars also exist. Guitars are recognized as one of the primary instruments in blues, country, flamenco, rock music, and many forms of pop. There is also a solo classical instrument. Guitars may be played acoustically, where the tone is produced by vibration of the strings and modulated by the hollow body, or they may rely on an amplifier that can electronically manipulate tone. Such electric guitars were introduced in the 20th century and continue to have a profound influence on popular culture. Traditionally guitars have usually been constructed of combinations of various woods and strung with animal gut, or more recently, with either nylon or steel strings. Guitars are made and repaired by luthiers.