Five Grand Ayatollahs answered a question about using drums and cymbals in mourning ceremonies.
Question: Is it allowed to use drums and cymbals in mourning ceremonies for Imam Hussain (AS)?
The Grand Ayatollah Sistani: There is no problem.
Question: What is your view about drums and cymbals for coordinating mourning ceremonies in the month of Muharram?
The Grand Ayatollah Safi Golpayegani: The mourning ceremonies for Imam Hussain (AS) which include speeches, eulogies, and movement of mourning processions, and these are great religious traditions which keep alive the traditions of Ahlul Bait (AS), and are signs of understanding of the religion and showing the religious emotions. These religious displays must be as simple as possible and without the use of instruments, the spirituals greatness is more pronounced and its displays are more educational; these decorations especially using instruments which according to religion are forbidden, are obstacles in the mourning ceremonies, and prevent paying attention to educative sense of these ceremonies.
Question: What is the ruling about using drums and cymbals in mourning and other ceremonies?
The Grand Ayatollah Makarem Shirazi: The use of drums and cymbals in these ceremonies as per usual traditions, and (as) there is no inappropriate music in them; there is no problem.
Question: What is the ruling about using musical instruments (local or others) like drums, cymbals, etc. for mourning Imam Hussain (AS)?
The Grand Ayatollah Khamenei: The use of musical instruments is not suitable for mourning ceremonies of Imam Hussain (AS), and it is appropriate that the ceremonies are held in traditional ways as per older times. Of course there is no problem using drums and cymbals in traditional ways.
Question: Is beating drum in mourning ceremonies for Imam Hussain (AS) in the streets, considered as music?
The Grand Ayatollah Rouhani: Beating drum in mourning ceremonies for Imam Hussain (AS) is not music and it is allowed, and I do not think that the Shias who love Ahlul Bait (AS) consider mourning ceremonies at the start of the night as inconvenience.
source : shafaqna