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: Philippe de Monte Purcell, Henry Bach, Johann Sebastian
John Harbison India Indonesia Gamelan sitar
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.