What is the ruling on a wife’s father allowing his daughter’s wedding ceremony to include music and songs, and is he sinful for that?

If the father allows a reprehensible celebration and is pleased with it, he incurs sin merely by his approval, for approval of the reprehensible is reprehensible. If he was able to prevent the celebration in his home and did not, he incurs sin by not preventing it. If he is unable to prevent it, then he must denounce it according to his ability and in accordance with the Sharia (definition) guidelines for enjoining good and forbidding evil, in order to absolve himself.