Inside a pipe organ

Not too many people have the opportunity to explore the inside of a pipe organ, so I thought it would be fun to look behind the glorious case-work of our beloved Holtkamp pipe organ and see—from the organ tuner’s perspective—the array of pipes and the view toward the high altar and north window from inside the chamber.

One can see the variety of pipe shapes, and construction either of metal (mostly a tin alloy) and wood. Some pipes are tuned by a sleeve that is gently knocked up and down with a narrow tuning iron. This sharpens or flattens the pitch. Other wooden pipes have “stoppers” inserted in the top of the pipe, which again are gently knocked to bring the pipe to pitch. These stopped pipes sound at twice their length because of the column of air inside the pipe being “stopped” rather than open at the end of the pipe.

The reed stops, which often have resonators somewhat in the shape of a trumpet or oboe, are tuned by adjusting a wire which sits against a brass tongue in the boot or base of the pipe. The sound of this tongue vibrating against a block when the wind is admitted into the base of the pipe is then “amplified” by the resonator, and, depending on the shape and scale of the tongue and resonator, gives the sound desired. That can be like a trumpet or, as the row pipes in the front of the rows of pipes illustrate below, like the Renaissance instrument, the Krummhorn.

Note also the various shapes and sizes of the different rows of pipes here. This is what gives a variety of sounds to the organ. The ability to combine these sounds in different and imaginative combinations is really one of the chief joys of being an organist!

Dr Jeffrey Campbell, Associate Director of Music & Organist