The music of Central Asia is as vast and unique as the many cultures and peoples who inhabit the region. Principal instrument types are two- or three-stringed lutes, the necks either fretted or fretless; fiddles made of horsehair; flutes, mostly open at both ends and either end-blown or side-blown; and jew harps, mostly metal. Percussion instruments include frame drums, tambourines, and kettledrums. Instrumental polyphony is achieved primarily by lutes and fiddles.