The four R-projects were born from the desire of scholars, archivists, librarians and musicians to develop research resources that provide access to our musical patrimony, namely, the music itself in manuscript and print; writings on music, both historic and contemporary; and depictions of music and music-making. The International Musicological Society (IMS) and the International Association of Music Libraries, Archives and Documentation Centres (IAML) jointly sponsor the creation of "R" when a monumental body of music and related literature and iconography remains in large part unexplored.
The principal function of the Rs is to create the necessary bibliographical research tools that identify and facilitate access to this extensive body of primary sources.
One R (RISM) deals primarily with music published or produced before 1900, two deal with literature about music (RILM and RIPM) and one with musical iconography (RIdIM). Three Rs (RISM, RILM and RIPM) produce extensive ongoing electronic publications, one (RIdIM) is preparing to do so. The Rs function on an international scale with the contributions of many scholars, librarians, archivists and institutions, present annual reports to the general assembly of IAML and every five years to the general assembly of the IMS, and organize various manifestations that encourage cooperation with and contributions to their respective publications.
RISM was founded by a committee chaired by Friedrich Blume; RILM and RIdIM by Barry S. Brook, and RIPM by H. Robert Cohen. Today, RISM, with headquarters in Frankfurt am Main, is directed by Klaus Keil; its President is Christoph Wolff; RILM, headquartered in New York, is directed by Barbara Dobbs Mackenzie; RIPM in Baltimore by H. Robert Cohen, and RIdIM in Zurich by Antonio Baldassarre.