Encyclopedias, Dictionaries, Guides, etc.
Try these first...
Oxford Bibliographies (Oxford Bibliographies offers exclusive, authoritative research guides. Combining the best features of an annotated bibliography and a high-level encyclopedia)
Oxford Music Online (Includes: The Oxford Dictionary of Music, The Grove Music Online, The Oxford Companion to Music) [more info]
Oxford History of Western Music ONLINE, an amazing narrative of the evolution of Western classical music.
Harvard Dictionary of Music (via Credo Reference-provides definitions of musical terms) [more info]
Baker's Biographical Dictionary of Music (via Gale Virtual Reference Library) [more info]
Contemporary Musicians (via Gale Biography in Context) [more info]
Continuum Encyclopedia of Popular Music of the World: Locations [more info]
Continuum Encyclopedia of Popular Music of the World: Media, Industry, and Society [more info]
Continuum Encyclopedia of Popular Music of the World: Performance and Production [more info]
Dissertations & Theses - Full Text [more info]
see also Interdisciplinary databases-Dissertations
Networked Digital Library of These and Dissertations
Search this database for international dissertations and theses. Worlcat is also a good option.
Emusicquest: Music In Print (scores) [more info]
The Faber Companion to 20th Century Popular Music (via Credo Reference) [more info]
The Garland Encyclopedia of World Music Online (via Alexander Street Press) [more info]
Harvard Biographical Dictionary of Music (via Credo Reference) [more info]
Hofmeister XIX (Free on the Web)
Index to printed music, music books & periodicals, illustrations, portraits & busts of composers published or produced between 1829-1900.
Index to Printed Music [more info]
International Dictionary of Opera (via Gale Biography in Context) [more info]
Metropolitan Opera Encyclopedia: A Comprehensive Guide to the World of Opera [more info]
The New Penguin Dictionary of Music (via Credo Reference) [more info]
RIdIM [more info]
The RIdIM database is designed to facilitate discovery of music iconography images by registered researchers, and the description of such images by registered cataloguers.
RISM A/II: Music Manuscripts after 1600 (more info)
RISM A/II: Music Manuscripts (1600-1800) in British and Irish Libraries
US-RISM Libretto Database (13,000+ citations for libretti in the Schatz Collection at the Library of Congress), available through the University of Virginia Library's online catalogue, Virgo (include keywords such as "operas" or "librettos" to find records).
***Note that tThe Schatz Collection microfilm is held in the Yale Music Library, Microforms, Reel 1904.***
Free Reference Sources Online...
All Music Guide (lists of recordings, sound samples) [more info]
Cantus: A Database for Latin Ecclesiastical Chant [more info]
Doctoral Dissertations in Musicology-Online [more info]
Music Theory Online Dissertation Index [more info]
Encyclopedia of Music in Canada [more info]