Jazz is an American musical genre born in the late 19th century in the African-American communities of New Orleans,2 Louisiana, which expanded globally throughout the 20th century. The musical identity of jazz is complex and cannot be easily delimited. First, although the term is often used to refer to a musical idiom (as is done, for example, when discussing classical music), jazz is actually a family of musical genres that share common characteristics, but do not individually represent the complexity of the genre as a whole; second, its various “social functions” (jazz can serve as background music for gatherings or as dance music, but certain types of jazz require attentive and concentrated listening) require a different angle of study; and third, the racial issue has always generated a profound debate about jazz, shaping its reception by the public.