RILM Music Encyclopedias This link opens in a new window(Note: Use Browse or Search to access content, clicking on images of books will only provide info about the book.) RILM Music Encyclopedias covers historical musicology, ethnomusicology, and theory, with topics ranging from popular music and rock, opera, instruments, and blues and gospel to recorded music and women composers. Its content spans multiple countries and languages—currently English, German, French, Italian, Czech, Dutch, Greek, Portuguese, Slovak, and Spanish.