While in Jerusalem, one of our favorite things to do (much to the chagrin of other tourists and worshippers, I am sure) was to take advantage of the amazing acoustics in the cathedrals and sing hymns as a group when we visited the different holy sites. It was always fun to sing hymns about Christ at the very place (maybe) that they happened, but that joy was multiplied as we sang in the cathedrals.
These short clips, unfortunately, highlight much of me and little of anyone else singing (since I was holding the camera), but if you can overlook that part it gives you a good sense of the awesome acoustics in those cathedrals.