Seth Godin in Tribes: We Need You to Lead Us has some interesting ideas about how leaders come to be and how ideas spread, stressing that change comes about through groups of people organized like a tribe: an interconnected group of people with a leader and an idea.
The difference between a tribe and just a group is explained in the book in terms of how they're formed, in that the leader of a tribe finds similarly minded people to form into a movement for an idea.
This is packed with case studies to explain what Godin sees as effective means to create change in and out of a corporation. It is, unfortunately, a little repetitious, almost like Godin was adapting a speech into a book form. So I recommend listening to the unabridged audiobook if you can instead.