Praise be to Allah.
1 – It is not permissible to attend wedding parties that involve evil actions, such as singing that is accompanied by music or that includes indecent words. The fact that this is widespread among people does not mean that it is permissible and should not be denounced.
2 – Not attending these parties is not regarded as severing the ties of kinship, rather it is protecting oneself from seeing or hearing evil. Your family and relatives should understand that you would be keen to attend and take part, were it not for the evil things that they do.
3 – If a person who is invited to such an event knows that there will be evil things happening and that he is not able to denounce them, it is not permissible for him to attend.
Ibn Qudaamah (may Allaah have mercy on him) said in al-Mughni (7/214): If a person is invited to a wedding feast in which evil things will take place, such as wine, musical instruments, etc, and he is able to attend and remove those evils, then he must attend and denounce them, because then he will be fulfilling two duties: accepting the invitation of his Muslim brother and removing evil. But if he is not able to denounce them then he should not attend. If he does not know about the evils until he gets there, he should remove them. If he cannot, then he should go away. Something similar was stated by al-Shaafa’i.
It says in Fataawa al-Lajnah al-Daa’imah:
If wedding parties are free of evils such as men mixing with women and indecent songs, or if you attend then these evils will be changed, then it is permissible to attend, so as to share in the occasion of joy. Rather it is obligatory to attend if there is some evil that you can remove.
But if there are evil things in these parties that you cannot denounce, then it is haraam to attend them because of the general meaning of the words of Allaah (interpretation of the meaning):
“And leave alone those who take their religion as play and amusement, and whom the life of this world has deceived. But remind (them) with it (the Qur’aan) lest a person be given up to destruction for that which he has earned, when he will find for himself no protector or intercessor besides Allaah” [al-An’aam 6:70]
“And of mankind is he who purchases idle talks (i.e. music, singing) to mislead (men) from the path of Allaah without knowledge, and takes it (the path of Allaah, or the Verses of the Qur’aan) by way of mockery. For such there will be a humiliating torment (in the Hell-fire)”
And because of the many ahaadeeth which condemn singing and musical instruments.
From Fataawa al-Mar’ah, compiled by Muhammad al-Musnad, p. 92.
And Allaah knows best.