Knobs, pedals and stacked keyboards - when put together properly - create a grand instrument for worship.

This instrument, the organ, is the focal point in many churches, such as Grace Episcopal Church in Gainesville. And what makes the organ so unique isn't just the booming sound that comes out of the pipes, but also all those knobs and buttons that can be used in myriad ways to create the sound.

But David Burton-Brown, director of music and organist at Grace, said the organ does more than just let out a strong sound.

"I think its best attribute is that it supports the congregational hymn singing so well," he said. "One can continue to build through the choruses on the organ and people don't feel as if ... a wall of sound has dropped in on me. There's no foreboding about the sound as a curse to the ear of the listener."

Grace Episcopal members and organist David Burton-Brown have been enjoying their new organ, made by the Canadian company Casavant Freres, for about a year now.

Before each performance, the organ is like a blank canvas, and Burton-Brown said the organist can pull the knobs and buttons to customize the sound.

For example, when Robert Poovey, an organist from St. Paul's Episcopal Church in Rochester, N.Y., and consultant on the new organ at Grace, held a concert at the church, Burton-Brown came in beforehand and set all the organ's controls.

Poovey "has all of his thoughts for the concert on Sunday set on these (knobs, pedals and buttons)," Burton-Brown said. "They were blank before he got here at a certain level, and that's what I do to when I prepare for a concert or a worship service."

With so many buttons, pedals and keys, playing the organ involves a whole different skill set compared to most instruments. Nevertheless, Poovey and Burton-Brown said the instrument's quirks are what make it special.

"Then there is the actual practicing of pushing these buttons at the right time," Poovey said. "It does have a scientific aspect to it, the way that we can combine these things and there are certain rules that we know work. Sometimes the fun of rules is breaking them ... but also there is art, and in the end the art trumps the science."

The organ's sound can also be manipulated to make other instrument sounds, like the trumpet, tuba or flute.

"What is most critical is that if the instrument is well built and is voiced perfect for the room, then size almost doesn't matter," Burton-Brown said.

Poovey added, "every single one is sort of designed precisely (for) its own place, so you might find a very tiny instrument in one place in a very, very small room."

Poovey plays a 20th century Skinner organ at his church in New York and formerly played a five-keyboard organ at St. Luke's Episcopal Church in Atlanta.

"Organists have to use their ears in a bit of a different way than a pianist or an instrumentalist because they can certainly change the tone," Poovey said. "You can literally pull out all the stops."

Burton-Brown performs this same feat each week to prepare for Sunday worship.

"Part of the recipes that (Poovey) comes up with for sound, as I do, is predicated on what historical practices and what period was in a given country," Burton-Brown said. "So is manipulating these sounds so they sound like 17th century Germany."

The organ has been around for centuries and takes years to master. Both organists began with the piano, but later switched to the organ. Burton-Brown has played the organ for 35 years and Poovey has been playing for 45 years.

Learning to play the piano, Burton-Brown said, is almost a prerequisite to becoming an organist.

"Music is one of the few disciplines that causes the brain to exercise right and left brain activities at the same time," Burton-Brown said. "There is the technical side, the right and wrong, the black and whiteness of whether the music is being played or executed. Then there is the artistic side that says, ‘Ah yes ... I can make it just a little bit unique by doing something to it.'"