1. Articles from print and online dictionaries and encyclopaedias: in-text citation
The in-text citation for substantial authored articles in reference works (both online and in print) contains the last name of the author(s) of the entry followed by the year of publication.
(McClymonds and Heartz 2001) or (Walsh 2007)
Stravinsky’s The Rite of Spring was premiered on May 29 in the Théâtre des Champs-Elysées in Paris and provoked a riotous uproar from the audience (Walsh 2007).
Articles from print and online dictionaries and encyclopaedias: reference list
Articles from dictionaries and encyclopedias can be cited in author-date format by adapting the notes and bibliography recommendations (CMOS 14.234). The reference list entry has a format similar to contributions to a multi-author book. If the reference work is online, provide an indication of the format and the date of access.
McClymonds, Marita P., and Daniel Heartz. 2001. "Opera Seria." In Nisard to Palestrina, 485-93. Vol 18 of The New Grove Dictionary of Music and Musicians, edited by Stanley Sadie. New York: Grove's Dictionaries.
(Last Name, First Name,)
Walsh, Stephen. 2007. "Stravinsky, Igor (Fyodorovich)." In Grove Music Online. Oxford University Press, online ed. Accessed September 16, 2019. http://www.oxfordmusiconline.com/.