The Origin of "Cool"
Who knew that the term "cool" is not mere slang like "peachy" or "groovy" but a concept embedded deep in the west African culture, which, in turn is the drumbeat of American culture. No matter what overheated activity the body is involved in, "cool" demands a serene facial expression. Across west African languages "cool" is synonymous with calm, beauty, tranquility, peace, reconciliation, gentleness and healing. Many rituals in west African religions are aimed at cooling the spirit. Partaking in a tribal dance -- vibrant, precise, ritualized, composing the face with a "cool" mask -- joins you with your ancestors, reconciles you with your family, and restores you to repose. You become not only "cool-headed" (capable of moderation and self-control) but "cool-hearted" (a certain collectedness of the mind). 
It might pay to remember this. Yes, being cool embodies "looking smart" and knowing all the right moves, but this same "cool" is also what helped the U.S. plantation slaves survive their ordeal. Or not only to survive but to fuel the engine of the vibrant culture of song, music, and movement that dominates musical entertainment today, from Dixieland to Death Metal.