It was after dinner when the haunting call permeated the night air! The Common potoo!  The descending 5 or 6 notes sounded absolutely bizarre, and without question was one of the strangest bird calls we have ever heard. I carry my tiny policeman’s flashlight in my video case, all kept close at hand tonight in case this bird did show, and within moments, we were set up on the 2nd floor balcony, within 10 meters of the bird.  This is the resulting photograph. It would call every few minutes, pumping his body with enthusiasm as if playing some kind of musical pipe with each note emitted.  Often the bird would sally forth to catch an insect, returning to the same branch.
Have a listen to one of the strangest bird calls I have ever heard: