The mbira dza vadzimu is a traditional instrument of the Shona people. It consists of a wooden board with staggered metal tines, played by plucking with the thumbs and the right forefinger. The mbira is often placed inside a hollowed-out gourd (deze) to amplify the sound and add a buzzing quality, traditionally achieved by attaching bottle caps or shells to the resonator. The music is polyrhythmic and cyclical, used in religious ceremonies (Bira) to contact ancestor spirits. In the 20th century, Thomas Mapfumo adapted mbira rhythms for the electric guitar, creating 'Chimurenga' music.