The Medieval Era was an era of music that was divided through liturgical (church music) and secular. (non church music)
Gregoria's chant was invented also known as plainchant.
It is an early form of counterpoint. (Polyphony showing contrast voices)
A form of viewing music made by a monk names Guido de Arezzo.
Music slowly drifted from liturgical and moved into the freewilled, more independent.
Changes in hyms and chorales. By Martin Luther the German.