What is harmony and why is it so important? When referring to a group of people and their attempts to accomplish a goal, harmony is the spirit of unity of purpose that the group has in working together to make that goal happen.
It has been found that, two or more people working together in harmony can create results that are vastly superior to the results that those same people could have accomplished on their own, right next to one another but not working together. Whenever a whole group of people are working together in harmony, something automatically forms as a result. It is called a mastermind, which is kind of like an extra mind that encompasses all of the ideas and thoughts of everyone in the group. It allows for new levels of creativity and progress that can not and do not exist withing the minds of each individual. In this particular case, it is actually true that the sum is greater than the parts which make it up.
Notice above that unity is mentioned. It would seem to one that knows even the basics of mathematics that five people working towards a goal and one person working against that goal would really just count as four out of the six working for the goal due to the one negative person cancelling out one positive person. But that simply is not how things work. If even one person is out of harmony with the others, the mastermind and all of it’s potential stop existing until harmony is restored.
More on how the mastermind principle works here