It took three decades for the international career of RSGM (Die rationalen und soziologischen Grundlagen der Musik) to take off. But the start of an inventive reading of the book—not only reconstructing the text and its intellectual background, but using it in order to elaborate new sociological empirical works—only began at the end of the twentieth century. The purpose of this paper—which is the first step of an ongoing research—is to re-examine in a constructive way the contributions of Weber and Simmel (his first sociology of music of 1882) which converge and complement one another in a striking way. While twentieth century cultural sociology struggles to renew its relevance and capacity to reveal new empirical fields, the first sociology of music seems to be resistant and well prepared to repress the expected decline of “old” sociologies. We must read them again in order to build a new sociology of music.