Important: Note that the formats for citing Grove Online given for each article when you click on the author's name are in the British style of formatting citations. Do not use those formats. Use the following formats to cite Grove Online:
For a footnote:
Malcolm Gillies, "Bartok, Bela, 1: 1881-1903," Grove Music Online, Oxford Music Online (accessed May 20, 2012).
For a bibliography entry:
Gillies, Malcolm. "Bartok, Bela, 1: 1881-1903." In Grove Music Online. Oxford Music Online. Accessed May 20, 2012.
Also note that Grove articles are lengthy, with each section of an article having its own author. Be sure to cite the title of the article section and its author in your footnotes and bibliography.