[Ancient Greek] instruments are known from descriptions, paintings and archaeological remains, which allow us to establish the timbres and range of pitches they produced.
And now, new revelations about ancient Greek music have emerged from a few dozen ancient documents inscribed with a vocal notation devised around 450 BC, consisting of alphabetic letters and signs placed above the vowels of the Greek words.
The Greeks had worked out the mathematical ratios of musical intervals – an octave is 2:1, a fifth 3:2, a fourth 4:3, and so on.
The notation gives an accurate indication of relative pitch.