Breathe In Breathe Out

There was a blonde that went to the hair salon with headphones. Before the barber started cutting her hair she told him "Make sure not to knock the headphones off my head". So the barber was sure not to. The next time, the blonde said the same thing "Do not knock the headphones off my head". The barber again, did what he was told. The third time she went, she told the barber again "Don't knock the headphones off my head", this time though, the barber accidentally knocked them off. As soon as the headphones fell off, the blonde dropped to the floor unconcious. The barber picked up the headphones and listened, and this is what it said "Breathe in, breathe out, breathe in, breathe out...."