Deacon Greg Kandra gives a thumbs down to projecting music on a wall at liturgy. Not every church is arranged for this to work. Some places like my parish are arranged antiphonally and there is no optimal space to project unless we removed our baldacchino and installed a two-sided screen. Other parishes don’t have a large-enough space on a wall to do it.
But suppose your parishioners worship all facing the same direction and the wall up there is pristine and clear of clutter. Would you do project? Why or why not?