At the left, you see a picture of the tetrachords in the Bound and the Full systeem. At the right, you see a picture with the names of the tones. It is in de diatonic form. And there were also no lines like we use them nowadays. They used a system of loose signs.
Every tone has a different sign.
The instrumental notation is a bit easier. One uses for that the 'Convention of Bellerman'. This implies that we regard the sign 'C', which indicates the same note in the vocale and instrumental notation, equally with our tone 'a'. Still, when we transcribe the scores, we assume that the real height of the tones would have been a tierce lower. Scientists have searched long for scores to see how the Ancient people noted their music.