Mademoiselle K’s First AlbumThis paper is the fruit of a recent research during which I observed the work (concert, rehearsals, recording studio sessions) of a French female singer songwriter, Mademoiselle K, when she was working in Paris on the creation of her first album, Ça me vexe (Capitol Music and roy Music, emi Music France, 2006), in a style between rock and French chanson.The paper analyses the way one of the songs is elaborated and structured through a process of a collective negotiation, which concerns parameters such as its duration, the order and sound contrasts of the verses, and the choruses. This whole operation is quite long and it involves a considerable number of people in addition to the original composer of the song : the other musicians, the producer and, for some aspects, even the manager and the editors.By observing this process, I show that the song structure is not some free individual creation by one single artist (the “author” in a legal conception), but that it is the result of a cooperation carried out on the basis of conventions (stylistic conventions for example).