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The Stoa Consortium:johannes Tinctoris Theoretical Works
This site is an overview of the life and work of Johannes Tinctoris. It explains several important details on his work in notation and musical composition. Also makes reference to his musical dictionary (the first musical dictionary in...
PBS
Classics for Kids: Musical Dictionary
This online music dictionary offers more than just definitions. Most terms have vocalized pronunciations and audio examples, as well.
Other
Tonalsoft: Encyclopedia of Microtonal Music Theory
Find an online encyclopedia specializing in microtonal music theory.