Hydroponics 1 for Laptop Orchestra, by Ambrose Field
For: As many performers as there are available laptops and equipment, and conductor.
Duration: 12 minutes minimum.
Each performer will need: one laptop computer, microphone, any sound processing or generation program, and an individual loudspeaker so that the computer system is a self-contained instrument without need for a unified, external public address system. Each performer will need a small Perspex tank of water. Size may vary between performers, but the audience must be able to see your hand gestures. Construction of a basic hydrophone You will need a hydrophone microphone for this task. If you do not have one, you can construct your own. The following web reference (last checked March 2007) has good, detailed construction details: sonar- fs.lboro.ac.uk/uag/downloads/bender2.pdf. The following basic version also works well: Use a small Piezo Ceramic microphone disk. These are extremely in-expensive. Solder two wires from a shielded connecting cable to a jack plug suitable for your equipment directly from the contacts on the surface of the disk. Cover the disk and exposed connections in an epoxy resin based solution and leave to harden. Electrical safety in the work is your responsibility, so remember to consult your health and safety manual before undertaking electronics work, and keep all electrical equipment and power cables safely away from water!
The role of the conductor in the work is to synchronise the performance, and split the composition into sections: (1) Smooth Sounds (2) waves (3) drips (4) turbulence. Write the section number on a back of a large card, and hold it up when 3 minutes has elapsed. You may freely repeat sections, and are free to experiment with the order of the sections.
Place hydrophone in water tank. Keep laptop and mains electricity well away from water tank! In rehearsal, assign one processing algorithm of your choice to the sounds picked up live by your hydrophone. This processing can be as simple or as complex as you like: filtering, reverberation, resampling, sample triggering, are all good examples. Decide as a group whether you wish to share information with each other on the choice of processing algorithms, or not. You may not change your processing algorithm during the piece: your task is to explore the sounds it can make by changing the nature of the water sounds arriving at your computer. Dry your hands if you need to operate the computer, do this carefully and visually each time. Create sounds in your water tank as indicated by the conductor. Each section lasts roughly three minutes, and note that section timing and order is controlled by the conductor.