What would be the best acoustical positions for the choir and organ? First, it’s important to note that the physical location of the organ keyboard is one thing and the locations of the pipes or speakers is another. The type of organ or keyboard can make a difference as to where to best place it. An organ is typically played in a reverberant space. Organ music is written so that the reverberation left over from the prior note mixes with the sound of the next note to form a chord. It is important to protect the reverberant part of the sanctuary for the sake of the organ. The organ is usually located in a position that easily and loudly stimulates the reverberation of the hall in which it is located. If you move the organ, you change the relationship between the sound generated by the organ and the reverberation of the hall. The ceiling often has impact on how the sound is stored and diffused throughout the space. If you move the organ, it will change how the sound is fed to the ceiling, changing the way it sounds in the hall. Organs are often located along the centerline of a church so that they can stimulate as much reverberation in the room as possible.
It’s a good idea to contact the organ manufacturer or installer before moving the organ. They usually have a lot of experience matching the organ to the hall.
Everything pertaining to the organ also applies to the choir. Except that the choir must also be able to hear themselves. Placing the choir in a gallery allows some of the sound to be held within the gallery. The choir sound heard by the congregation is “pre-blended” by the walls, ceiling, and floor of the gallery. This makes their sound sweeter, more full, and almost larger than life. The people in the choir can hear themselves and each other because they are essentially singing in a room that happens to have a large door (the opening to the rest of the church). Choir members who can hear themselves and each other better stay in tune and on tempo better.
If you move the choir too far out into the open they struggle against the thinness of their sound. However, there are some churches who tire of the old world sounds of worship. The reverberant organ and choir may no longer be a valued part of their service. Perhaps the organ is being moved forward to join a contemporary praise band. Likewise, the choir may be being turned into the backup vocalists for the lead voices in the band. In this case, gut the old gallery, turn it into a spotlight deck and get on with the show. But, be aware that now their is a whole new issue of acoustics to deal with: the interaction of amplified sound within your reverberant hall.