What is most beneficial is a balance between yin and yang. What is harmful is imbalance. The complementary duality of yin and yang may be utilized to understand the workings of the natural universe, in which nothing is isolated and everything is related. There is an inherent order in all things, which is given by the elements of yin and yang.
Imbalance creates problems.
Anyone who pays the least attention will also perceive that in music there is the same reconciliation of opposites. Harmony is composed of differing notes of higher or lower pitch which disagreed once, but are now reconciled by the art of music. For harmony is a symphony, and symphony is an agreement. In like manner rhythm is compounded of elements short and long, once differing and now in accord. But when you want to use them in actual life, then the difficulty begins, and the good artist is needed.