Traditional Zambian music is rooted in the beliefs and practices of Zambia's various ethnic groups and has suffered some decline in the last three decades. Traditional Zambian music once had clear ritual purposes or was an expression of the social fabric of the culture. Songs were used to teach, to heal, to appeal to spirits, and for mere enjoyment. Despite the decline of traditional music, its influences can still be heard in many of today's Zambian musical forms. The ubiquitous African "call-and-response" can be heard in almost every Zambian song no matter what the style. Traditional drum rhythms and polymeters are evident in many different kinds of Zambian music. Contemporary popular forms such as Zambian Kalindula also exhibit traces of traditional music in the finger-picking style used by guitarists.