Thomas James Mathiesen (born April 30, 1947) is an American musicologist, whose research focuses on Ancient music and the music theory of ancient and early periods. A leading scholar of the music of Ancient Greece, Mathiesen has written four monographs and numerous articles on the topic.
Mathiesen's research centers around Ancient music, in particular, he is a leading scholar of the music of Ancient Greece.[1] This subject is the topic of his four book-length studies, Aristides Quintilianus on Music in Three Books: Translation, with Introduction, Commentary, and Annotations (1983), Ancient Greek Music Theory: A Catalogue raisonné of Manuscripts RISM B/XI (1988), Greek Views of Music (1997) and Apollo's Lyre: Greek Music and Music Theory in Antiquity and the Middle Ages (1999).[2] Other topics he engages in include the history of music theory, particularly of Medieval music and Renaissance music.[1] His scholarship includes the topics of "textual criticism, editorial technique, bibliography and codicology".[1]
Mathiesen established in 1990 the online project Thesaurus Musicarum Latinarum (TML) and led it until 2015. Due to his efforts TML became a world-wide known database of early music treatises, with a free access.[3]