I think I've heard the phrase before once by a younger guy at work talking about it. But I thought he said something like "Hairspray bands". But I get your drift about "Metal hair bands". One comes to mind is POISON. Like these guys with incredible hair styles and they wave it all over the place. Mostly METALICA type bands of the 80's. And you thought it was going to stop there eh? Well, the music and bands have gone off the edge now. All gloves are off and they keep growing wierder by the hour.