Is it permissible to disobey a father who insists on holding a wedding party that includes forbidden things like lewd singing and dancing, and threatens his son with displeasure in this world and the hereafter, as well as boycotting the celebration, knowing that he does not pray?

There is no obedience to your father in what he requested, and his anger towards you for your obedience to Allah the Almighty is misplaced anger. Strive to advise him and remind him of Allah the Almighty and of the prohibition of music. We advise presenting fatwas on music to him. As for his abandonment of prayer, it is a grave sin and one of the major transgressions.