The Chicago Manual of Style (CMS) is the source most often used for Music Department assignments and papers. Be sure to check if your instructor requires CMS 16th or 17th edition. Here are some links to help you:
Link provided by Dr. Alan Dodson in 2022. Use this guide when preparing citations for your music theory essays.
Important: Author-date format is not the same as footnote-bibliography format. The former is used in music theory courses, the latter in music history.