Question 17: What is the ruling on praising Allaah by singing and reciting the Aayaat (Qur’aanic verses) in a musical tone to attract the non-Muslims to accept Islaam and warn the Muslims of committing sins?
Answer: This act is not permissible for the following reasons:
1- Singing is Haraam (prohibited) as it is a kind of vain talk dispraised by the Qur’aan where Allaah (Exalted be He) says: And of mankind is he who purchases idle talks (i.e. music, singing, etc.) to mislead (men) from the Path of Allaah without knowledge The doer of such an act is threatened with painful punishment.
2- The Masjid (mosque) is highly venerated, thus they should be free from sins including singing; the Masjid is only built to remember and mention Allaah (Glorified and Exalted be He) there.
3- An even graver prohibition is that people chant the Qur’aan in a musical tone as is done in singing. This act entails degrading the Qur’an and dealing with it like the songs chanted for entertainment.
4- It is obligatory to call non-Muslims to embrace Islaam and to encourage sinful Muslims to repent to Allaah, but this should be done according to the Shar`ee (Islaamic legal) ways, not those forbidden, or newly invented in religion...read more here.