Is it permissible to attend a wedding banquet that contains no illicit things, if it was preceded by a wedding party that included musical instruments, singing, and other illicit things?

If the wedding feast was preceded by abominations such as musical instruments and revelry, then it is not permissible to attend it, because the wedding is a single unit, and a Muslim's attendance for the food is considered an endorsement of the abomination, and it diminishes the standing of the righteous. The Hanafis have stipulated that if the invited person is someone whose example is followed and he is unable to prevent the abomination, then he must leave and not sit. Likewise, Sheikh Muhammad Al-Musnad issued a fatwa (definition) stating the impermissibility of accepting such invitations, except for whoever is able to remove or mitigate the abomination.