乐者乐也。君子乐得其道,小人乐得其欲。以道制欲,则乐而不乱;以欲忘道,则惑而不乐。· Where there is music there is joy. Superior men rejoice in attaining to the course; and smaller men in obtaining the things which they desire. When the objects of desire are regulated by a consideration of the course to be pursued,there is joy without any disorder. When those objects lead to the forgetfulness of that course,there is delusion,and no joy.
(The Book of Rites [of the Warring States Period])