Bede's Ecclesiastical History of England, ed. by A.M. Sellar, [1907], at sacred-texts.com
THEODORE came to his Church in the second year after his consecration, on Sunday, the 27th of May, and spent in it twenty-one years, three months, and twenty-six days. Soon after, he visited all the island, wherever the tribes of the English dwelt, for he was gladly received and heard by all persons; and everywhere attended and assisted by Hadrian, he taught the right rule of life, and the canonical custom of celebrating Easter. This was the first archbishop whom all the English Church consented to obey. And forasmuch as both of them were, as has been said before, fully instructed both in sacred and in secular letters, they gathered a crowd of disciples, and rivers of wholesome knowledge daily flowed from them to water the hearts of their hearers; and, together with the books of Holy Scripture, they also taught them the metrical art, astronomy, and ecclesiastical arithmetic. A testimony whereof is, that there are still living at this day some of their scholars, who are as well versed in the Greek and Latin tongues as in their own, in which they were born. Nor were there ever happier times since the English came into Britain; for having brave Christian kings, they were a terror to all barbarous nations, and the minds of all men were bent upon the joys of the heavenly kingdom of which they had but lately heard; and all who desired to be instructed in sacred studies had masters at hand to teach them.
From that time also they began in all the churches of the English to learn Church music, which till then had been only known in Kent. And, excepting James, of whom we have spoken above,the first teacher of singing in the churches of the Northumbrians was Eddi, surnamed Stephen,invited from Kent by the most reverend Wilfrid, who was the first of the bishops of the English nation that learned to deliver to the churches of the English the Catholic manner of life.
Theodore, journeying through all parts, ordained bishops in fitting places, and with their assistance corrected such things as he found faulty. Among the rest, when he charged Bishop Ceadda with not having been duly consecrated, he, with great humility, answered, "If you know that I have not duly received episcopal ordination, I willingly resign the office, for I never thought myself worthy of it; but, though unworthy, for obedience sake I submitted, when bidden to undertake it." Theodore, hearing his humble answer, said that he should not resign the bishopric, and he himself completed his ordination after the Catholic manner. Now at the time when Deusdledit died, and a bishop for the church of Canterbury was by request ordained and sent, Wilfrid was also sent from Britain into Gaul to be ordained; and because he returned before Theodore, he ordained priests and deacons in Kent till the archbishop should come to his see. But when Theodore came to the city of Rochester, where the bishopric had been long vacant by the death of Damian,he ordained a man named Putta,trained rather in the teaching of the Church and more addicted to simplicity of life than active in worldly affairs, but specially skilful in Church music, after the Roman use, which he had learned from the disciples of the blessed Pope Gregory.