To consider in room acoustic design:
Song and acoustic instrumental music require a certain response from the room, both for the person singing/playing and for those listening. For justice to be done to the music, adapted reverberance is needed in the premises. With music practice, however, too long reverberation can be tiresome, so there should be a certain absorption adapted to the shape and size of the room.
If an absorbing ceiling is used, it is an advantage to use sound-scattering objects - along the walls, for instance - to create a pleasant, even acoustic quality throughout the whole premises.