Corridos Sin Fronteras - Information from Smithsonian Institute about the native Mexican folk music tradition. Includes a graphical timeline, music samples, videos, guides and background material for teachers.
Eras Online - Basics about the major periods of classical (art) music, with terms, composers, RAM audio examples, and purchase links. From Essentials of Music, sponsored by Sony Classical and W. W. Norton.
Gallery Music - (Sung by church and chapel "bands" in the UK in the 18th and 19th centuries) Includes articles, sample scores and MIDI files, links, and organizations.
History in Song - Includes annotated texts about American history, from Revolutionary War songs to 1960's anti-war protests.
The History of Czech Music - A brief history of Czech music, from the Middle Ages to the 20th century; Biographies and work of important composers. (Radio Hudba, Czech Republic)