Gregorian chant developed mainly in western and central Europe during the 9th and 10th centuries, but people wrote new songs and changed the old ones later. Many people believe an old story, which says that Pope Gregory the Great wrote the songs. Most people who study the history of music believe that kings such as Charlemagne brought music from Rome to their kingdoms in France and Germany. When Charlemagne's people sang these songs, they changed the songs. This new music became Gregorian chant.