For my birthday we saw the Harlem Gospel Choir perform. They played in the Minoriten Kirche (built 1300). We sat just below the side pulpit hanging from the wall to the left. The Choir sang at the main alter.
The choir was great, and the lead singer even took an opportunity to sing unamplified in the huge hall of the church. A big old church like this has an almost natural reverb, and you could tell that as he was singing he was kind of playing with that effect. We sat real close to the singers performing on the main alter. There were maybe 500 people in the audience. Below is an albeit weak recording of one of there songs (there is no picture, just sound). Despite the poor recording the songs were strong and come through.