Commemoration Ceremonies A few points regarding Mourning Ceremonies, Part 1 Generally speaking, it is not permissible to put on music in mosques or Hussainiyas but using drums and cymbals is permissible on the condition that the tune is appropriate for mourning. Furthermore, the loudspeakers of the Majalis must not disturb the neighbors. Removing shirts at the time of chest-beating is haram if it happens in the presence of non-mahrams.
Rather, indeed, precaution demands that mourners must steer clear of such an act even if it is not seen by non-mahram women. Nonetheless, there is no problem in leaving a little of one's chest uncovered for chest-beating.