This paper sets out to discuss the use and power of music in representing social identities, concentrating on the more specific case of the Brazilian nation, which has made itself a complex and all-embracing socio-political unit in spite of the great diversity and the great inequalities to be found within its borders. It is well known that what appears to be its most uniform feature, the use of a dominant language, is actually quite fragmented, due to the influence of various co-existing systems of production, cultural models and social hierarchies, which change on a daily basis. Although this diversity seems to be underwritten by daily practice and independent of debate and official encouragement, the same cannot be said of the search for national unity. It is obvious in the case of most of the action undertaken with this end in mind, that questions such as exclusion and the imbalance and arbitrariness of power have been eliminated. Besides, certain alert individuals are wary of this insistence on the construction of a nation, since the role of the old national states throughout the world seems to be disintegrating in the face of the proliferation and growing importance of social, economic and cultural relations at a supranational level. It is therefore hardly surprising that the twentieth century is considered to be a milestone in both the rise and fall of efforts to achieve Brazilian national unity. Amongst these efforts, music has played a prominent role, as I shall endeavour to show.