This collective and bilingual work (of 512 pages) is a text compilation of the acts of the International Congress of Tunis about modality, which was organized by the CMAM and the ISMT from December 7 to 9, 2017. The book aims to open the debate in the context of a questioning around the notion and the dialectical relations that modality can maintain with the essence of modal or monohull music of oral tradition, their identity and their continuity.