As a musician and an ethnologist, I am teaching in the University of Bordeaux. With a particular interest in Latin America, I started in 1992 a research on the popular singers who improvise their songs. That took me to the land of Nordeste, the northeastern region of Brazil. There, I found amateurs of improvised poetry : the cantadores and their admirers, gathered in nocturnal sessions called cantorias. The passion for the word expressed in accordance with the rules of art is a cultural element shared throughout Latin America. Singing poetry and the tournament between poets are appreciated. But in Nordeste, people give supreme importance to the total improvisation of the sung verses. That is the art of the repente (the word means sudden), a local tradition whose vivacity is remarkable. Its actors are much more numerous than before. They are called repentistas, cantadores or violeiros. Repentistas because they always renew their verses ; cantadores, they are popular artists capable of singing any subject proposed by the public ; violeiros, they accompany themselves with a viola, a kind of guitar emblematic of their profession. Urbanization has boosted the evolution of the tradition of the repente. It appeared in the 19th century in a semi-arid and rural area of the interior of Nordeste, called Sertão. Droughts caused periodic exodus and the Nordestinos constituted the main contingent of migrant workers in the country. For half a century, they have participated in the industrialization and the construction of large cities. This rural exodus has depopulated the Sertão, whose itinerant poets of old were changed into emigrant poets, following their public towards the cities and adapting their art to the modernity. The urban project needs social adjustment and cultural adaptation. I will expose the tradition of the repente, art of the word whose ethics is spontaneity and adaptation ; then, how improvising poets have conquered new production spaces, diversifying their activities ; finally, the reason for the development of a popular expression in the cities where cultural diversity and the pressure of modernity are real-life : the improvisers practice a form of animation combining creation and mediation.< Réduire