They were located in Paris, Cologne, Soissons and Metz, all under the supervision of the Schola Cantorum in Rome.
Origin of Church Modes in music.
750 years later modes are tranformed into the major and minor scales
Development of the Gregorian Chant
590-604 C.E. Development of the Gregorian Chant. It can also be called plainsong or plainchant and was named after Pope Gregory the Great. The Pope was believed to have brought it to the West.
<a href='http://www.youtube.com/watch?v=Dlr90NLDp-0' >An example of a Gregorian Chant
Beginnings of part song in fourths, fifths and octaves.