Books about world music are at these call numbers:
Use advanced search in Library Search with terms such as names of countries, geographical regions, ethnic groups, instruments, and the term music or folk music.
General books on instruments are at ML460 in Reference and General Stacks. Dictionaries of instruments are in Reference at ML 102 .I5.
Some of the best sources in the library and on the Web are:
This page includes resources about the music of countries, regions, and peoples throughout the world.
Information and resources under the tabs above will also be useful, particularly: Dictionaries & Encyclopedias; Articles; Books; Audio & Video; and Interlibrary Loan.
Books on ethnomusicology are at ML 3797-3799. Here are two: