The Columbia University Libraries have an extensive collection of music-related materials from and about Latin America, the Caribbean, Portugal and Spain. Most resources encompass part of the collections of the Gabe M. Wiener Music & Arts Library. Holdings include books, journals, scores, and recordings.
Here are some useful tips for searching in CLIO, Columbia Libraries' online catalog.
You should definitely explore Columbia Libraries' LibX widget, a plug-in that enables incredibly convenient right-click searching across CLIO and the web for a variety of print and electronic sources.
You may also be interested in some help with citation management software (such as Zotero and End Note) to help streamline and organize your research.