Dream Songs for the Flame Organ

It might be the strangest and most improbable concert you will ever witness. Charles Anderson talks to Dunedin musician Alastair Galbraith about his upcoming flame organ performance in Nelson.

Alastair Galbraith first read about it in the pages of a Victorian hardcover book appropriately entitled Sound.

Galbraith knows sound. The Dunedin-based musician has recorded numerous albums with some of New Zealand's foremost musicians. But this was something different.

The engraving depicted a gentleman entertaining an audience. He had one very large steel pipe. The text explained that into it he slowly pushed a flaming bunsen burner. Then he pulled it out. Then he waited. Then "the audience was agog as peels of thunder swept thorough the theatre".

"It sounded like one of the most exciting sounds I had ever read about," Galbraith says. "I had to try it out to see if it had musical potential."

Galbraith's project has taken him nine years, and is his contribution to about 150 years of this only vaguely understood combination of art and physics.

In 1859, Petrus Leonardus Rijke, a professor of physics at Leiden University in the Netherlands, discovered a way of using heat to sustain a sound in a cylindrical tube open at both ends.

He used a glass tube about one metre long and 3.5cm in diameter. Inside it, about 20cm from one end, he placed a disc of wire gauze. With the tube vertical and the gauze in the lower half, he heated the gauze with a flame until it was glowing cherry red.

Upon removing the flame, he obtained a loud sound from the tube, which lasted until the gauze cooled down.

Music to Galbraith's ears. What if that effect could be extrapolated? What if instead of one glass tube, you had 25, and the bunsen burners were all connected to keys? What if you could play a chord with flame?

This is Galbraith's flame organ. Next week, he will test it on Nelsonians.

Reams and reams of notes, information, studies, applications and music float around his head. There is so much that he doesn't even know what people would find interesting any more.

"The whole effect is one of the trickiest things to understand and it's not even yet fully understood," he says.

Galbraith knew nothing about physics before he made his first flame organ, so he went back to first-year university textbooks that tried to explain Rijke's effect, all in the same badly written way.

For 100 years, no-one had seriously studied the Rijke effect, but Galbraith convinced Creative New Zealand and the Ministry of Science, Research and Technology of the virtues of his flame organ.

He spoke to the foremost expert in the effect, a Russian based at an American university who studied how heat and vibration affect the flow of air over the hull of a boat.

Apparently, even when we speak, the amount of sound released raises the temperature in the immediate vicinity of where the air is vibrating. "One thing relates to another, until you are looking at something so complex even this expert can't explain how it starts."

Only a handful of flame organs exist in the world. Some look spectacular, but sound limp. Galbraith says his sounds like medieval trumpets. In full flight, it looks mystical.

Play a chord with flame and each note trails on for a different period. The note dissolves, falling at different rates.

"You expect it to be horrible and dissonant, but it's really quite stunning."

What was dissonant was the data Galbraith collected from his organ.

According to the best physicists in the world, the volume of the note was supposed to be highest when the blazing hot gauze was put at the mouth of the tube, but it wasn't. The physicists said the note for a Rijke tube was meant to start high and then drift away, but it didn't. It moved in waves.

"That was really unusual and that is something that is not recorded anywhere."

If someone would look at it and work out what is being missed, who knows what could happen, he says. "This is what music can bring to science."

He wants to help publish some short papers on his findings and then hand them on to someone who can do something with them.

Galbraith is usually writing songs and building a few other instruments, but has never been involved in something that has required so much concentration. "Physics is absolutely fascinating," he says. "It teaches you that life is infinitely fascinating at any level you choose to look at it."