But the fickleness and flunkeyism of the minstrels served them well. When they had been expelled from France because of their libellous tongues, many of them were invited over to England by William de Longchamps, bishop of Ely, who governed the kingdom during the absence of Richard the Lionhearted, and who, anxious to blind the people to the vices of his régime, hired these singers to proclaim his virtues to the public. Thus art is continually being called to the glorification of vice and tyranny. But for such services the minstrels had their reward. So useful did they make themselves, wherever they went, that they received increasing marks of respect. When the Christian revival of the tenth and eleventh centuries came, they made themselves its apostles, singing the new songs in place of the old. The acting troupes presented miracle plays on Biblical or traditional religious subjects and were presently invited by the clergy to perform on the church steps or even within the church itself. Centuries later they had attained such dignity that they could organize themselves into guilds under the protection of the reigning prince. They had their aristocratic and exclusive labor unions, were employed to organize town bands, and in many places formed the nuclei for court orchestras. Of the music of these minstrels in the early centuries we know next to nothing. There existed nothing at the time that could be called musical notation, and tradition, if it has brought any of their songs down to us, has changed them in the course of the centuries. We have, it is true, a spirited song, supposed to have been written on the death of Charlemagne, calling on Franks and Romans to lament and honor the lost sovereign. But this was probably not purely popular in its origin, else it would not have attained to writing. The words of a few ditties have been preserved. The celebrated ‘Song of Roland,’ dating from Charlemagne’s time, was supposed to have been sung as late as the battle of Poitiers in 1356. But what chiefly assures us of the vigor of the popular music of the time was the wide variety of types it contained--patriotic songs, love songs, songs satirical and historical, and many others. We know also that the music was original and alive, quite in contrast to that of the church. For when the popular tradition was taken up by the aristocratic Troubadours and Trouvères in the eleventh and twelfth centuries, the melodies had an independent character that proves a vigorous antecedent development. The old modes continued to dominate church music up to the fifteenth and even sixteenth centuries. But the songs of the Troubadours and Trouvères are often written in the modern major scale. The popular music of the ninth and tenth centuries had undergone the development that the church did not attain until five hundred years later.