At the launch of “A Dao: A study of history and tonal system”, researcher Bui Trong Hien said he had heard elderly artists lament that modern performances of “a dao” are “not proper, not within the framework,” but the question of “what is proper?” always remained unanswered. It was this dilemma that prompted the author to reconstruct the complete tonal system of this thousand-year-old music genre. All knowledge gained from the 9-year journey “to find a classical model of A Dao” is condensed into a 600-page book consisting of 7 chapters. The author delves into the historical aspects, cultural space, and tonal system of the traditional art form, decoding many mysteries of ca tru - the oldest music genre in Vietnam. “A Dao: A study of history and tonal system” is not just the story of preserving and promoting traditional values of Vietnam but also documents the talent and contribution of women to the history of the country’s cultural arts./.