Must the marriage project be canceled if the family insists on holding a musical wedding ceremony where there is no mixing?

If singing is accompanied by music, or contains forbidden lyrics, or incites passion and arouses desires, then it is prohibited. However, if it is free from these prohibitions, then it is permissible. If the family insists on prohibited singing, do not obey them and do not cancel the marriage. Seek help from Allah and from good people to convince them. If that does not work, then get married despite their disapproval. For whoever seeks Allah's pleasure, even if it displeases people, Allah will be pleased with him and will make the people pleased with him.