Music Appreciation: Its Language, History and Culture (openstax) Introduction to works representative of a variety of music traditions. These include the repertoires of Western Europe from the Middle Ages through the present; of the United States, including art music, jazz, folk, rock, musical theater; and from at least two non-Western world areas.
Music Appreciation (Lumen Learning) An exposition of the philosophy, principles, and materials of music from the Baroque Period to contemporary period with illustrative examples from the Baroque Period, Classical Period, Romantic Period, Contemporary Classical Music and Popular Music.
Open Music Theory (2021, Gotham et al., CC BY-SA 4.0) An open-source, interactive, online “text”book for college-level music theory courses. Supports active student engagement with music in the theory classroom.
Sound Reasoning: A New Way to Listen (OpenStax). Designed to help students listen, this course by Prof. Anthony Brandt encourages students to be self-reliant--to get up close to the music, without mediation or interference.