This article sheds light on a surprising phenomenon on the record market: the sound volume of music has been growing continuously for more than 30 years. This increase is the product of the uncertainty of employment in music industry. To draw the attention of market intermediaries on whom their success depends, artists and record companies want the volume of their music to be as high as that of their competitors, giving rise to a “loudness war.” The analysis of this “war” shows, first of all, how the competition and the material devices it relies on create new conventions in the production of music. Namely, as the high volume has become ever more desirable it is also increasingly associated with a greater competitiveness. Secondly, this analysis allows to see by which mechanisms a configuration of competition leads to a collective transformation of musical contents. Finally, the “loudness war” reveals the heterogeneity of the principles that frame music production. It highlights the conflict between the emerging conventions of competitiveness on the one hand and the historical aesthetico-technical conventions on the other hand in the music industry. Indeed, the technical personnel is organizing a resistance to this “war” in order to protect the aesthetic characteristics of recorded music, the historical foundation of its role in the division of labor.