The most famous unseen hair in popular music belongs, without question, to Erykah Badu.
"The investigation and adjudication process operates in most parts unseen and unheard," he said.
It has been, because of the difficulty of showing it, one of the most famous unseen films, a rival to Orson Welles' The Other Side of the Wind.
"It went from being highly sophisticated, lucrative, and, for the most part, unseen, to being much more brutal, in-your-face, democratic kind of crime, which affected lots of people and created widespread fear," he said.
The most significant unseen presence in the narrator's young life, however, is that of a man whom his mother apparently loved before she married his father and whom she cannot, or will not, forget.
Terrorism and the activities of non-state groups fighting throughout the Middle East, and spilling into Europe - and potentially an increasing threat to Russia and China - is drawing nation states into a conflict which is for the most part unseen.
There would be a sudden burst of a few shots, then a crescendo in which, it seemed, every marine in the vicinity was firing his weapon at an enemy who was, for the most part, unseen; and then it would stop, briefly.
Most go unseen and unrecorded.
