The wealth and commercial activity of the Low Countries, known as Flanders, Brabant and Hainault, had now become greater than that of any other part of Europe, Italy perhaps excepted. The organization of the Communes, which began, indeed, in France as early as the tenth century, naturally reached a greater extent during the crusades, when so many of the higher and more energetic nobility were absent in the Holy Land, since the defense and order of the people at home had to be maintained by those who were left behind. Under these circumstances, the power naturally drifted into the strongest hands available, which quite as naturally were those of the capable merchants and manufacturers of the burgher class. Hence the condition of society, while much hampered by the restrictions of the guilds requiring children to be brought up to the occupation of the parents, was nevertheless more favorable to the freedom of the individual than at any previous period. These social elements combining with the wealth aforesaid, and the public spirit which has always distinguished the mercantile classes engaged in foreign commerce upon a large scale, united to form an environment favorable to the development of art; and, as music was the form of art which happened to be most in demand at the time, the effects of the stimulating environment were immediately seen. It was perhaps partly in consequence of the burgher character of the classes most engaged in music in Flanders that the form music there developed should have been so exclusively vocal. All the work of this school, extending over two centuries, was either exclusively vocal, or written with main consideration for the voice, the instrumental additions, if any, having never taken on a descriptive or colorative character.