I'd like to say it was something French.
After all with the exception of Alan Stivel nothing remotely pleasant has emerged from that country in the last 50 years:
However as was the case with traditional African music which Black Americans took to their heart and transformed into the Blues, the French Americans took French folk music and removed from it all vestiges of harmony, timing and melody to produce cajun:
Yes, it took the Americans to transform something pretty appalling into the truly dreadful. I can only think that this is the aural manifestation of the bitterness that French descendants feel towards the Anglo Saxon invaders who took the Southern United states from them. The only reason the musicians are smiling is because they know it's total crap but English speaking idiots are still paying good money to come and listen to it.
No, French music and it's cacophonous descendent are truly awful but years of searching for new styles of music have left me firmly convinced that in the sewage works of organised noise there can be only one winner, a style that is so truly dreadful in ways so subtle and cruel that we in the West can only cover our ears and wonder who the phuq thought that up, I give you Gamelan:
http://www.youtube.com/watch?v=b8hf5vXq6Zc&playnext=1&list=PLEDB462...
Beat that.
All challenges should be supported by links to phonographic evidence.