International directories of music: sources, literature, iconography, journals

The 4 "Rs" - RISM (Répertoire international des sources musicales), RILM (Répertoire international de littérature musicale), RIdIM (Répertoire international d'iconographie musicale), RIPM (Répertoire international de la presse musicale) - have developed under the aegis of the International Association of Music Libraries, Archives and Documentation Centres (IAML) and the International Musicological Society. They are based on a world-wide collaboration of professional librarians and researchers. After several decades of existence, they are able to offer mostly online access to several hundreds of thousands of music items: printed and manuscript sources, music literature, iconography, and coverage of 19th century journals.