A Clear Explanation for The Prohibition of Music Part 5

While the general verdict on singing is its prohibition, most jurists have excepted in their books the singing of women in wedding ceremonies. The reasons of this exclusion are the sayings of the Ahl Al-Bayt peace be upon them like the saying of Imam Al-Sadiq (pbuh) “The earning of a songstress in weddings is considered lawful, but not the one that men enter on her”(1) . If her earning is considered lawful then her action which she earns by is also considered lawful, because according to Islamic laws, if an action was prohibited then the money that was made by the action would also be considered unlawful.
Ayatollah Sistani went along with the jurist in recording this exception in his book. Even though at the end he does not except it as an exception as it will be made clear. He states: “The exception of singing is the singing of women in weddings if it does not include another haram action like hitting the drums, using words of diversion(bāṭil), and the entrance of men on them (during this action) in a way that they hear women's voices which arouses sexual temptations. However, it is an obligational precaution not to consider this an exception.”

So, the singing of women in weddings is considered lawful if its condition is observed. The condition is quiet clear, there has to be no other taboo action such as using unlawful words, the usage of prohibited instruments (we will talk more about that later), men hearing them while they are singing in a way that men's sexual desire is stimulated.
However, the Ayatollah does have an obligational precaution to stay away from this singing, which means one can either stay away from this kind of singing or refer to another qualified jurist and follow the verdict of this most learned jurist and copy him in this particular ruling.