Because MOM and OER Commons search multiple OER websites in one search--they are your best places to begin.
Audio files freely available or available under CC license.
Open Courseware materials include syllabi, written lectures, assignments, readings, videotaped lectures, and audio lectures.
Freely available images or images available with a Creative Commons license.
Openly accessible scores and sheet music.
Open textbooks or textbooks available with Creative Commons licenses.
Freely available, open access or Creative Commons licensed videos.