I don't know if this is true or not, but playing everything stupid loud here and across the river, seems to be the norm. Although in Laos it never happens in that fashion, mostly just at parties, funerals and weddings. But it would never start that early or end very very late.
But I digress. My wife explained that they play things loud like that to scare away ghosts. So, using that (rather insane) logic. Firing up the system at 0600 hrs would scare away the ghosts in the machine.
I can't wrap my head around such profound stupidity even after nearly 2 decades. But, try to argue logic with a Thai or Lao.