The music for this ending is a gregorian chant. I suggested this because it is a sacred song, composed when the church was in the hight of power.
The estimated classification I would apply to my film would be a 12A. Using the above guide for film classification I decided this film has mild psychotic violence. This film would not be an 18, or 15 as there are no sexual references or moderate/extreme violence. The bbfc website has all the information about film classification and the guidlines behind them. This is where i found my information.