There are three main types of modern acoustic guitar: the classical guitar (nylon-string guitar), the steel-string acoustic guitar, and the archtop guitar. The tone of an acoustic guitar is produced by the strings' vibration, amplified by the body of the guitar, which acts as a resonating chamber. The classical guitar is often played as a solo instrument using a comprehensive fingerpicking technique. The term fingerpicking can also refer to a specific tradition of folk, blues, bluegrass, and country guitar playing in the US.