Bloom, Ken. Broadway: Its History, People, and Places, an Encyclopedia. 2nd ed. New York: Routledge, 2004.
Articles on people and places (theaters, restaurants, etc.)
Butterworth, Neil. Dictionary of American Classical Composers. 2nd ed. New York: Routledge, 2005
Brief, mostly factual bios of perhaps a thousand composers. Little stylistic insight.
Cohen, Aaron I. International Encyclopedia of Women Composers. 2nd ed., rev and enl. New York: Books & Music USA, 1987 [at Ritter Library]
A very good biographical dictionary of women composers with biographies, work lists, and bibliographies. Also includes several helpful indexes.
Feather, Leonard & Ira Gitler. Biographical Encyclopedia of Jazz. Oxford ; New York : Oxford University Press, 1999
Gänzl, Kurt. Encyclopedia of the Musical Theatre. 2nd ed. 3 vols. New York : Schirmer Books, 2001. [At Ritter]
Holden, Amanda, ed. New Penguin Opera Guide. London: Penguin Books, 2001.
Articles on ca. 850 composers and their works. Works appear under composer’s name (unlike New Grove Opera). No articles on techniques or periods.
** Kernfeld, Barry, ed. New Grove Dictionary of Jazz. 2 vols. London: Macmillan; New York: Grove's Dictionaries of Music, 1988.
Scholarly treatment of people and subjects in jazz. The 2nd edition of this is incorporated into Grove Music Online, and should be preferred to this older print version. http://www.oxfordmusiconline.com.
Kirchner, Bill, ed. Oxford Companion to Jazz. Oxford ; New York : Oxford University Press, 2000.
** Komara, Edward, ed. Encyclopedia of the Blues. 2 vols. New York: Routledge, 2006.
Larkin, Colin, ed. Encyclopedia of Popular Music. 4th ed. http://www.oxfordmusiconline.com/
The most extensive English-language encyclopedia on popular music. Thousands of articles on musicians, bands, and (to a limited extent) concepts. Jones has the 2nd and 3rd editions in print.
** Sadie, Stanley, ed. New Grove Dictionary of Opera. 4 vols. London: Macmillan; New York: Grove’s Dictionaries of Music, 1992.
Gives opera the New Grove treatment with expanded coverage including articles on specific operas and several helpful indexes. Also available as part of Grove Music Online.
** Sadie, Stanley, ed. New Grove Dictionary of Musical Instruments. 3 vols. London: Macmillan; New York: Grove's Dictionaries of Music, 1984. [at Ritter Library]
An excellent source (though now somewhat out of date) for information on all types of instruments from around the world.
Vinton, John, ed. Dictionary of Contemporary Music. New York: E. P. Dutton, 1971.
Primarily entries on people, with brief bios and lists of works, but also includes entries on topics and places.
** indicates a particularly basic or important resource