Hello, I've been trying to find a definitive answer to the vexed question of when plainchant moved, if indeed it ever did, from 4-line staves to 5-line staves. As someone interested in manuscript leaves of plainchant of the 14th to 16th centuries, I have examples of both systems of notation. I understand that by the 16th century, the convention was that sacred music was written on 4-line staves and secular music on 5-line staves. However there are anomalies.
I have a finely illuminated leaf of Gregorian chant (?) dated, (supposedly) 1390 and which is written on 5 line staves. Is this possible?
Any thoughts/opinions gratefully received.