The acoustics of the recorder

We are all familiar with the recorder, most of us may have played it at school and now some of us may be experiencing (or suffering) it again at the hand of a keen primary school child. The instrument itself is simple, the use of an air jet creates a vibrational energy source within a slightly tapered cylindrical air column and the pitch is controlled by opening or closing the finger holes along the length of the tube. But the fundamental acoustical conundrum that remains unexplained is: ‘Why do they sound so bad?’ Perhaps its just me, perhaps there are people out there that enjoy the squeaky grate of the instrument and the sound of 20 school kids playing London Bridge at a variety of tempos … but I am yet to find one!