1) "Grove" originated as a print dictionary (encyclopedia really) that has been in continuous publication since 1878 in many updates and editions. Accessible in two versions:

The New Grove dictionary of music and musicians.  29 volumes. In print.

Grove Music Online comprises the full text of The New Grove Dictionary of Music and Musicians, The New Grove Dictionary of Opera, and 4 others.  Updated periodically.

"Grove" in either print or online form is "the first stop for music research."

In English. Extensive bibliographies and composer "works lists".  Biographies and subjects; arranged alphabetically.  Contains extensive articles on the music of geographical locations. Search by location or by specific musical instrument.

Examples:    Florence Price   Scott Joplin  George Walker

Fela Kuti   Miriam Makeba    Beyonce   Kanye West   Bessie Smith  Sidney Bechet

Jazz  Tongue-Clicking  Thomas Dorsey   Fisk Jubilee Singers

2) "MGG"

Die Musik in Geschichte und Gegenwart : allgemeine Enzyklopädie der Musik.  27 volumes. In print.

In German. Extensive bibliographies and composer works lists.  Arranged in 2 sections: Sachteil (subjects) and Personenteil (biographies).  Arranged alphabetically in both sections.