Australian Indigenous music includes the music of Aboriginal Australians and Torres Strait Islanders, who are collectively called Indigenous Australians; it incorporates a variety of distinctive traditional music styles practiced by Indigenous Australian peoples, as well as a range of contemporary musical styles of and fusion with European traditions as interpreted and performed by Indigenous Australian artists. Music has formed an integral part of the social, cultural and ceremonial observances of these people, down through the millennia of their individual and collective histories to the present day, and has existed for 40,000 years. The traditional forms include many aspects of performance and musical instrumentation which are unique to particular regions or Indigenous Australian groups; there are equally elements of musical tradition which are common or widespread through much of the Australian continent, and even beyond. The culture of the Torres Strait Islanders is related to that of adjacent parts of New Guinea and so their music is also related. Music is a vital part of Indigenous Australians' cultural maintenance.