[1] It is the largest organization of its kind and the only entity operating globally to document written musical sources.

Shortly after its founding, A.H. King called RISM, "one of the boldest pieces of long-term planning ever undertaken for the source material of any subject in the humanistic field.

The work of RISM in compiling a comprehensive index fulfills a twofold purpose: for one, music documents are protected from loss, and for another, they are made available to scholars and musicians.

The RISM Digital Center is primarily responsible for developing Muscat, the online cataloguing tool for the organization.

RISM's main focus is its electronic database containing descriptions of musical sources from around the world.

Included are, among other things, information about: The manuscripts are described in detail with respect to copyist and place and time of origin.

In addition, many works include a music incipit, that is, the opening notes or measures from important movements or sections of a piece.

Apart from the stated intention of opening the way to the primary source for researchers and performers, this sort of catalog provides attractive possibilities for other areas of interest and inquiry as well.

The database provides information not only about the dissemination of works by composers who are still well known today, but also a wealth of knowledge about those many creative musicians who were highly regarded in their day, but are currently either little known, or even forgotten.

The RISM series are: In addition to these, working groups conduct projects to document libretti surviving in their respective countries.

Over 78,000 printed editions by 7,616 composers (arranged alphabetically) from 2,178 libraries were documented in the nine volumes of the series (published 1971–1981).

The CD-ROM version of the accumulated database produced and published by K. G. Saur in Munich was discontinued in 2008.

The entirety of Series A/II is in the online database, and several printed catalogs have been published based subsets of the RISM records.