SHAFAQNA – The Grand Ayatollah Khamenei answered a question about broadcasting music from Mosques.
Question: Is there any problem religiously for broadcasting happy/joyous music from Mosques to celebrate birthdays of infallible Imams (AS)?
The Grand Ayatollah Khamenei: It is obvious that the Mosque has a special religious status, so if broadcasting music in there, is against the sanctity of the Mosque; it is Haram, even if the music is not of the inappropriate type.
Source: Ajwebatul Istefta’at, Question 399.