START HERE WITH OUR WEBPAGE ON INDONESIA RESOURCES:
Here are some resources from that page to focus on:
Try this book for a good place to start when doing research on Indonesia. Be certain to read the Introduction to the Bibliography (pages 555-564) and see the bibliography that follows (pages 564-667):
Historical Dictionary of Indonesia (3rd edition) by Audrey Kahin
Lanham : Rowman & Littlefield, 
Paper Copy: Kroch Library Asia Reference (Non-Circulating) DS633 .C75x 2015
Online Copy: https://newcatalog.library.cornell.edu/catalog/9917119
Here is an older (1994) but useful research book containing annotated title listings of major and standard sources of information covering a large range of topics:
Indonesia by Gerald H. Krausse and Sylvia Engelen Krausse
Oxford, England ; Santa Barbara, Calif. : Clio Press, ©1994.
Paper Copy 1: Kroch Library Asia Reference (Non-Circulating) DS615 .K73 1994 Note: Shelved in dictionary stand by Asia desk.
Paper Copy 2: Kroch Library Asia Z3271 .K728w 1994Online Copy: https://newcatalog.library.cornell.edu/catalog/9567886
The Leiden Catalog is a great place to look for additional resources on Indonesia
Bibliography of Asian Studies
This database references mostly western-language articles and book chapters on all parts of Asia published since 1971. This is a good place to start for articles.
Southeast Asia Digital Library
Contains a number of resources about Southeast Asia, including a specific page for Indonesia.
You might also find some sources on music in Indonesia here