COLLECTIONS OF LINKS:
Handbook of Latin American Studies from Library of Congress:
https://guides.loc.gov/handbook-of-latin-american-studies

DIAMM (the Digital Image Archive of Medieval Music)
https://www.diamm.ac.uk/

Portuguese Early Music Database
http://pemdatabase.eu/

Best of the Web The New York Public Library (no longer updated but useful nevertheless)
https://www.nypl.org/weblinks/2473

Digital Resources for Musicology
DRM (ccarh.org)

NATIONAL LIBRARY SITES:
Europeana, a portal for searching holdings of many European national libraries and other important research libraries (replaces older theeuropeanlibrary.org):
https://www.europeana.eu/en

significant individual sites:
Library of Congress--search can be customized for music
https://catalog.loc.gov/vwebv/searchAdvanced

Bibliothèque nationale de France
bnf.fr

Biblioteca Nacional de España
http://www.bne.es/es/Inicio/index.html

Deutsche Nationalbibliothek (DNB)
https://www.dnb.de/DE/Home/home_node.html

Österreichischen Nationalbibliothek
https://www.onb.ac.at/

composer sites:
Portuguese composer Oscar Lorenzo Fernândez (1897-1948):

https://lorenzofernandez.org/

Brazilian composer José Maurício Nunes Garcia (1767-1830)
josemauricio.com.br