Introduction Francesco Pelosi and Federico Maria Petrucci; 1. Scala nature and music: two models in Philo's thought Carlos Lévy; 2. Music and Plutarch's Platonic cosmos Bram Demulder; 3. The harmoniser god: harmony as a cosmological model in middle Platonist theology Federico M. Petrucci; 4. Alexander of Aphrodisias and musical models for ontological enquiries Laura M. Castelli; 5. How to resist musical dogmatism: the aim and methods of Pyrrhonian inquiry in Sextus Empiricus' 'Against the Musicologists' (Math. VI) Máté Veres; 6. Shifting epistemological perspectives in Ptolemy's 'Harmonics': from the science of sound to the study of music Andrew Barker; 7. Musical imagery in Clement of Alexandria and Origen: the Greek musical world revised and accepted Francesco Pelosi; 8. Plotinus on music, rhythm, and harmony Alexandra Michalewski; 9. Porphyry's 'Commentary on Ptolemy's Harmonics': questions of philosophic and scientific identity Harold Tarrant; 10. The music of the virtues in late ancient Platonism Dominic O'Meara; 11. Harmonics as theological paradigm in Proclus Stephen Gersh; 12. Calcidius on cosmic harmony Christina Hoenig; 13. Harmonia in Philoponus' 'Commentary on Nicomachus' introduction to arithmetic' Giovanna R. Giardina.