The letter "A"

a tree is a word. a word is a song. a song is a life. a life is a smile. a smile is a colour. a colour is a river. a river is a sea. a sea is a flight. a flight is a friend. a friend is a thought. a thought is a moment. a moment is a flower. a flower is a branch. a branch is a leaf. a leaf is a tree. a tree is a word.