There is a new rule change allowing piped in music to be played on 3rd downs, it looks like can only be played before the snap. More than likely ever SEC team will be implementing this. They played just a small loop (maybe 10-15 seconds) of just the "turn down or what" part of the song and then the bass kicks in. That part is pretty deafening so it works pretty well. Couple that with the crowd going nuts and it will be hard on the offense.
It really is not as big a deal as some are making it out to be.