premise: A tall, skinny guy with long black hair is walking while talking on a cellphone and carrying a drum on his head. hypothesis: A tall guy is singing and swinging his arms while walking down some stairs.
contradiction: A man who is walking while talking on a cellphone and carrying a drum on his head would not be singing and swing his arms while doing so, additionally, walking down stairs while swinging one's arms would be extremely difficult to do while carrying someone on one's head.