a modern and finished way. In this process of establishment as an urban and modern musical expression, the Carioca samba had the decisive role of samba schools, responsible for defining and legitimizing definitively the aesthetic bases of rhythm, and radio broadcasting, which greatly contributed to the diffusion and popularization of the genre and its song singers. Thus, samba has achieved major projection throughout Brazil and has become one of the main symbols of Brazilian national identity. Once criminalized and rejected for its Afro-Brazilian origins, and definitely working-class music in its mythic origins, the genre has also received support from members of the upper classes and the country's cultural elite. At the same time that it established itself as the genesis of samba, the "Estácio paradigm" paved the way for its fragmentation into new sub-genres and styles of composition and interpretation throughout the 20th century. Mainly from the so-called "golden age" of Brazilian music, samba received abundant categorizations, some of which denote solid and well-accepted derivative strands – such as bossa nova, pagode, partido alto, samba de breque, samba-canção, samba de enredo and samba de terreiro – while other nomenclatures were somewhat more imprecise – such as samba do barulho (literally "noise samba"), samba epistolar ("epistolary samba") ou samba fonético ("phonetic samba") – and some merely derogatory – such as sambalada, sambolero or sambão joia. The modern samba that emerged at the beginning of the 20th century is predominantly in a time signature varied with the conscious use of a sung chorus to a batucada rhythm, with various stanzas of declaratory verses. Its traditial instrumentation is composed of percussion instruments such as the pandeiro, cuíca, tamborim, ganzá and surdo accompaniment – whose inspiration is choro – such as classical guitar and cavaquinho. In 2005 Unesco declared Samba de Roda part of Intangible Cultural Heritage of Humanity, and in 2007, the Brazilian National Institute of Historic and Artistic Heritage declared Carioca samba and three of its matrixes – samba de terreiro, partido-alto and samba de enredo – as cultural heritage in Brazil. Also, in 2018, the prefecture of Salvador proclaimed Samba Junino, also known as Samba Duro, an urban variation of Samba to be part of its Cultural Heritage. Etymology and definition There is no consensus among experts on the etymology of the term "samba". A traditionalist view defends that the etymon comes from the Bantu was in the Diário de Pernambuco