RISMRISM contains over 1.4 million records for musical sources: music manuscripts, printed music, libretti, and treatises that are held in music libraries, archives, churches, private collections, and other institutions around the world. The bulk of the manuscripts dates from between the years 1600 and 1850. The focus of printed music is imprints up to 1800. However, you will find both older and newer sources in the catalog.
The RISM Catalog contains all of series A/I, A/II, and B/I. RISM's book publications in series B document groups of sources by topic. Most of the volumes in series B are not in the online catalog but can be consulted in well-stocked research libraries or to an extent online.