The following peer-reviewed journals are available freely online (open access). Most articles are in English, Spanish, or Portuguese, with a few articles in French or Catalan.
General Interest (not scholarly):
Look in these collections for documentaries or feature films related to your topic.
The encyclopedias in this section are in an online collection of encyclopedias and reference books called Credo Reference. Click on a specific title to see the contents of just that book, or go to Credo to search them all at once. Your search results will include the title of the encyclopedia or reference book the article came from.
Encyclopedia of Latin American Popular Music by 
Latin Music: Musicians, Genres, and Themes by 
Pop Culture Latin America! by 
Garland Encyclopedia of World Music, Vol. 2: South America, Mexico, Central America, and the Caribbean by 
Latin American Music Reader by 
Latin American Classical Composers by 