The mysterious didgeridoo is in a class of instruments called labrosones (so called because their sound is made by vibrating the lips), which includes reedless brass instruments like the trumpet and bugle. Labrosonic instruments are tubes modified to convert lip-based fart noises into music. A column of air within the tube, excited into a standing wave by the vibration of the player’s lips, produces a note, which the player can alter by changing her lip vibrations. The lowest note a labrosone can sound is determined by the length of the tube; longer tubes give lower fundamental notes—the valves on a trumpet actually change the total length of the tube in order to increase the instrument’s range.
Genuine didgeridoos are the only wind instruments crafted by animals for human use: They are made from eucalyptus trunks hollowed out by termites. After harvesting, these instruments enjoy little modification, apart from the addition of a beeswax mouthpiece and some surface decoration. Since artisans spend an inordinate amount of time wandering around inhospitable climates searching for eucalyptus trunks that the termites have gotten just right, genuine didgeridoos can be very expensive. Cheaper didges made from teak and bamboo are common, but in terms of tone, volume, and playability, you can build your own for just a few dollars and get as good—or better—results.
To get a sense of what you can do with a PVC didgeridoo, let’s make a “30-second didge” by adding a simple duct tape mouthpiece to some PVC. Grab a 4′ length of PVC plumbing.
Warning
If you’re cutting the PVC yourself wear a respirator and work outside, since the friction from the saw can heat the PVC enough for it to release gases; see Step 2 for a full discussion of the dangers of PVC fumes.
Use your fingers to clear away any rough snaggles from the edges, and then wash off any grease, grime, or grit that’s on the pipe. Take about 5″ of duct tape and wrap it around the pipe so that half the width hangs off the end (as shown in Figure 11-2). Tuck the duct tape into the pipe and give it a good rub; warmth and pressure encourage adhesion.
Now flip to Playing the Didgeridoo in Playing the Didgeridoo and give your didge a few experimental toots. Although a straight PVC didgeridoo will make an acceptable sound, it’s muffled and muddled, with few of the complex overtones that make the didgeridoo popular. Modifying the PVC didgeridoo—adding a proper beeswax mouthpiece, belling the end, and adding complexity to the interior of the didge—increases back pressure (making it easier to play a sustained note), brings out overtones, reduces the “PVC rattle,” defines the tone, and makes it easier to shift up from the fundamental drone. Finally, adding a pickup means being able to process and filter the didgeridoo’s sound—using software on your computer, store-bought guitar stomp boxes, or the effects and filters in later projects—and directly hook into an amplifier, PA system, or recording rig.
a propane torch with “pencil flame” end (If you can get your hands on a heat gun, like those used to strip paint, you can use that; it will heat the PVC enough to be malleable with less risk of charring it.)
a round-headed bolt, preferably one with a nickel- or dime-sized head
a long-necked plastic funnel (Look in the auto supplies aisle of your hardware store; a wide-mouthed kitchen funnel won’t work.)
a beer bottle
a respirator mask suitable for filtering organic solvent fumes