[Music: Intonation=Bar 1. Recitation=Bar 2. Mediation=Bar 3, Bar 4. Recitation=Bar 5. Termination=Bar 6, Bar 7, Bar 8.] Gregory arranged the mass in its present form, and prescribed a special introit for each psalm, and probably one for each division of the mass. The famous old anonymous hymns, the Te Deum, Magnificat, Benedictus, etc., had taken their place in the church service in its very earliest days; and the mass had gradually been formed by selection and arrangement of these. Another form which gradually grew up in the Church was the Sequence. This had its origin in a desire to allow the congregation more opportunity to take part in the musical service. In their oldest and purest form these sequences consisted of ornamental passages intoned on a single vowel,--as the final "a" of "jubila." These sequences illustrate in a striking manner that freedom from control of text which came so conspicuously into music in Gregory's time. This freedom, while it led to abuses of the church ritual, gave music a certain amount of independence as an art, and enabled it to develop more rapidly than it could have done had it been tied fast to the text. Nokter Balbulus, a monk of the famous convent of St. Gall, Switzerland, is said to have popularized the sequences in the ninth century by writing thirty-five special ones. Some of these are still used in the Roman Church. The convent of St. Gall, to which Nokter belonged, was a famous centre of musical culture in the eighth, ninth, and tenth centuries. The writing of special words for sequences was followed by others than Nokter; and in the end these reduced themselves to these five well-known texts: Dies Iræ, Stabat Mater, Victimæ Paschali, Veni Sancte Spiritus, and Lauda Sion. The Roman chant soon spread through Europe. The successor of Gregory was acknowledged by the Western nations as the Supreme Head of the united Church, and this, of course, tended to a general use of the same ritual. In 604 Roman singers were sent to England, and in 660 monks went to teach the Gregorian chant in Brittany. Paris had become the capital of France not long before that, and the Gallic service was now remodelled on that of Rome. The Roman ritual was introduced into Germany by Saint Boniface in 744, and it was probably made known at St. Gall about the same time. Charlemagne, in the eighth century, founded schools of music on Gregory's plan at Dijon, Cambray, Lyons, Orléans, and other French cities, and also at Regensburg, Würzburg, Mainz, and other German places.