Does the manager of a wedding hall bear sin regarding food waste and the singing that occurs in the hall?

It is not permissible to rent out a hall for parties that include unlawful singing, due to the generality of Allah Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." The manager must stipulate to the renters that they are not to commit unlawful acts. As for leftover food, the renters must be asked to take it to be given as charity, or the cleaning staff should collect it and the manager distribute it to those in need.