Fire and Bass: throughout this year we’re pairing up with teams of artists and makers to build three experimental ‘Soundscape Sculptures’. In this, our first in a series of posts, we profile the Fire Organ – the many headed hyrdra of flame tubes! 

The three tubed Fire Organ dancing to a single Concert C.

The three tubed Fire Organ dancing to a single Concert C. All photo credit: Ryan Johnson

Did you ever wonder why your earbud headphones are so bad at playing bass notes? It’s because bass has a size, and it’s big. Bass Is Big. That’s why big rigs rumble, and skateboards clatter. It’s why a deep church organ fills the room, but a violin fits in a suitcase. Its why a djembe is large, and a snare drum is small. Generally, if it’s big, it can make bass. If it is small it can’t.

You see, it turns out that sounds has a shape, and a Fire, or Rubens’, Organ dances in synchrony with the shapes of sound. Really, it’s like a drum, in reverse. It takes music in, and turns it into (flame) motion.

The Rubens' Organ team. Mark Rosin, Lee Sonko and Michael Kearney line up from left to right, with Isabelle on keyboard.

The Rubens’ Organ team. Mark Rosin, Lee Sonko and Michael Kearney line up from left to right, with Isabelle on keyboard.

For its first outing we introduced the Organ to Isabelle Engler, a classical pianist. The venue: American Steel, an industrial arts warehouse in Oakland, California. Joining us were the artists Lee Sonko and Michael Kearney.

The Guerilla Science artists and team set up for launch.

The Guerilla Science artists and team set up for launch.

Isabelle picked a couple of classics, the mathematician’s favourite J.S. Bach, and some Yann Tierson (of Amélie fame). As she played, and the haunting music floated through the air, the mix of oxygen and propane inside the tubes began to vibrate too. Each note, a sound wave of alternating high and low pressure, thrust the flaming gas out of the tube, mimicking the shape of the sound.

The lower the note, the longer the flame pattern on the Organ. The more extreme the difference in flame heights, the louder the notes.

The lower the note, the longer the flame pattern on the Organ. The more extreme the difference in flame heights, the louder the notes.

In theory, it’s a simple enough idea. Take a long metal tube, drill some holes in the top and pump in flammable gas. Add fire and you get a row of pretty candles. But, like a dancing snake, the real fun comes however when you play music and bass.

Windproof fire power: Outside at the Mathematical Sciences Research Institute, Michael Kearney tests the Organ in all weather conditions.

Windproof fire power: Outside at the Mathematical Sciences Research Institute, Michael Kearney tests the Organ in all weather conditions.

Unlike its single headed cousin, the Rubens’ Tube, or its two-dimensional generalisation, the pyro-board, the Rubens’ Organ responds cleanly to many layered beats, all at once. We used crossovers (those electronic filters that send bass to your subwoofer and high notes to your tweeters) to filter the highest notes to the shortest tube, and the lowest notes to the longest tube. We’ve built simple fire tubes before, you can read about them on our blog here and learn about the detailed math and physics on the Naked Scientists’ blog.

Over the coming year we hope to build an even bigger and even better version. We’re going to take it, and the rest of the sculptures to every music and art festival we can get to – all across America!  

This project is generously supported by the Mathematical Sciences Research Institute You can see more pictures from the build and this event on our Flickr site.