Textbooks can be another good place to begin looking. They often
cover topics in more depth than do the reference tools, but won't
always have information about the particular region or style you're
This book has chapters on North America (Native America), Africa (Ewe, Mande, Dagbamba, Shona, BaAka), North America (Black America), Bosnia and Central/Southeastern Europe, India (South India), Asia (Indonesia), East Asia (Japan), and Latin America (Ecuador).
This book has fun activities in some chapters, like directions for making your own traditional instruments. It also has an accompanying sound recording.
Instead of taking a geographic approach to issues in world music, Shelemay divides her book into themed chapters like The Music of Everyday Life, Music and Migration, The Study of Local Musics, Music of Worship and Belief, Music and Dance, Music and Memory, Music and Identity, Music and Politics, and Music in the Real World.
Each of these chapters has various case studies involving particular musical styles. A full list can be found in the contents section.
While this isn't exactly a text book, it is shelved near many of them and isn't exactly a reference book either. It gives a brief overview of many popular world music styles and is easy to use, as long as you take a quick look at the table of contents.
This book lives up to its title- it is indeed very short. Instead of approaching world music by cultural areas, it takes a topical approach with chapters titled: In the beginning...myth and meaning in world music; The West and the world; Between myth and history; Music of the folk; Music of the nations; Diaspora; and Colonial musics, post-colonial worlds, and the globalization of world music. There are good suggestions for further reading listed in the back.