Accented syllables in Ancient Greek had a higher pitch (τόνος) than unaccented syllables, and it was the rising and falling of the pitch that made Ancient Greek a musical language. The Greek word for accent is προσῳδία_ (Lat. accentus: from
N.—The accent heard in Modern Greek and English is a stress-accent. Stress is produced by strong and weak expiration, and takes account of accented syllables to the neglect of the quantity of unaccented syllables. Thus, shortly after Christ, ἄνθρωπος was often pronounced like a dactyl, φίλος like a trochee; and πρόσωπον, ἐννέα, were even written πρόσοπον, έννήα.
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].