In this article I discuss the practice of rhyme improvisation duel in rap, known as freestyle battles, in which, according to the early practitioners, the goal is to mock the opponent. Based on a research carried out for two years at the Battle of Santa Cruz, in São Paulo, I analyse how the musical and performance aspects contribute to alleviate the bitterness caused by the deride. While analysing the contents of the improvising speech, I propose to consider the mobilized categories - such as gender, age, race/color, class - operating as differential signs that yield a significance exclusively by means of the articulations achieved during each battle, and have no sense if viewed isolatedly.