Put the following events in order from earliest to latest earliest schools for church music are established pope Gregory founds schola cantorum development of neumes gregorian cha?

The earliest schools for church music were established first, followed by the development of neumes, which were early musical notation systems. After that, Pope Gregory I founded the Schola Cantorum to train singers and standardize liturgical music. Finally, Gregorian chant emerged as a significant form of church music during this period.