Porphyry’s Commentary on Ptolemy’s “Harmonics” is a unique document of Neoplatonic thought on music. Not only does it contain a thorough discussion of the perception and appreciation of pitched sounds, but it also gives us a hint of how the technicalities of music theory might have been taught to non specialised readers with a philosophical background; moreover, it is a treasure of quotations from lost authors and works.

The apparatus of this new edition includes all the emendations and conjectures that have been proposed by many scholars since Ingemar Düring’s 1932 edition and takes into account a few manuscripts that escaped the previous editor’s otherwise remarkable recensio. The boundaries of some quotations from ancient authors are redefined and many misprints corrected. Finally, the text of the Byzantine epitome of the Commentary is here edited for the first time.