Should the boycott of the daughter and her husband continue after a wedding ceremony that included singing and music, or should they be visited and kinship ties resumed thereafter?

What we advised you regarding not attending the wedding ceremony if it involves any forbidden acts does not mean boycotting your daughter and her husband altogether. Your not attending the ceremony is a boycott of the forbidden act, not of them. Boycotting a Muslim and abandoning them is not permissible except for a legitimate reason. The Prophet, peace and blessings be upon him, forbade turning away from one another and abandoning each other among Muslims. If this abandonment occurs between relatives, it is even more severe, for breaking ties of kinship is among the major sins.