The music of Australia has an extensive history stretching back to the Indigenous and colonial societies. Indigenous Australian music is a part of the unique heritage of a 40,000–60,000 year history which produced the iconic didgeridoo. Contemporary fusions of Indigenous and Western styles (exemplified in the works of No Fixed Address, Yothu Yindi, Christine Anu and Geoffrey Gurrumul Yunupingu) mark distinctly Australian contributions to world music. During its early western history, Australia was a collection of British colonies, and Australian folk music and bush ballads such as Waltzing Matilda were heavily influenced by Anglo-Celtic traditions, while classical forms were derived from those of Europe. Contemporary Australian music ranges across a broad spectrum with trends often concurrent with those of the US, the UK, and similar nations – notably in the Australian rock and Australian country music genres. Tastes have diversified along with post-World War II multicultural immigration to Australia.