The Rolling Stones have assimilated various musical genres into their own collective sound. Throughout the band's career, their musical contributions have been marked by a continual reference and reliance on musical styles including blues, psychedelia, R&B, country, folk, reggae, dance, and world music, exemplified by Jones' collaboration with the Master Musicians of Jajouka, as well as traditional English styles that use stringed instruments like harps. Brian Jones experimented with the use of non-traditional instruments such as the sitar and slide guitar in their early days. The group started out covering early rock 'n' roll and blues songs, and have never stopped playing live or recording cover songs.