Is working in a printing press that prints wedding invitations containing phrases such as "a musical band will perform tonight," or "a DJ will perform tonight," or "artist so-and-so will perform tonight" unlawful (haram)? And what should be done?

Singing accompanied by music is forbidden, especially if it contains phrases that incite instincts and arouse desires. Therefore, it is not permissible to write phrases such as "A musical band will perform tonight" or "Artist so-and-so will perform tonight" and the like, as this constitutes aiding in sin. Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression" (Al-Ma'idah: 2).