Unusual Guitar

Classical and flamenco guitars historically used gut strings but these have been superseded by polymer materials, such as nylon and fluorocarbon.
Modern guitar strings are constructed of metal, polymers, or animal or plant product materials. Instruments utilising "steel" strings may have strings made of alloys incorporating steel, nickel or phosphor bronze. Bass strings for both instruments are wound rather than monofilament.
• Body (acoustic guitar)
In acoustic guitars, string vibration is transmitted through the bridge and saddle to the body via sound board. The sound board is typically made of tone woods such as spruce or cedar. Timbers for tone woods are chosen for both strength and ability to transfer mechanical energy from the strings to the air within the guitar body. Sound is further shaped by the characteristics of the guitar body's resonant cavity.