Tech Tip:Guerilla Instrument Design


By Dennis Kambury

What do these things have in common: a frying pan lid, a knife, the cardboard tube from wrapping paper, a hat box, a large rubber band, a pepper grinder, and a stick? With a little treatment and imagination, they can all be used as musical instruments!

In the percussion section, your frying pan lid can serve double duty as a cymbal and, captured with a sampler such as the
Korg TRITON, as a metallophone - raw for gamelan-like tones, or filtered for more of a marimba-like sound. Strike it with the knife for a sharp, metallic attack; with the stick for a softer hit; or with your fingers for a muted effect. A small-diaphragm mic such as the Rode NT5 or the Neumann KM184 will do a great job of picking up the attacks and high overtones. With the addition of a AKG D112, the hat box becomes a kick drum - the bigger the hat, the deeper the kick. You could also stretch a large rubber band across the hole - tight enough to resonate - and make the hat box more of a tom. The pepper grinder can be multipurposed as well. Adjust the grind for the perfect shaker sound (an SM57 will do well here) or use it to strike the "cymbal." (Realizing the musical potential of pepper, Musician's Friend offers Vic Firth pepper mills for your grinding and striking pleasure).

While you've got the hat box and rubber band out you can also create a string bass. You can play it live with much the same effect as the traditional washtub bass, or use your sampler to make a more precise instrument. A large-diaphragm condenser mic such as the
MXL V57M or the Neumann TLM-103 would be a good choice here.

Add harmonic richness to your ad hoc orchestra with the cardboard tube, a large-diaphragm condenser mic, and your sampler. Blow in one end of the tube as you would a trumpet or digiridoo, and work it until you find the resonant frequency of the tube. You'll know it when you hear it! Sample this tone, and then with the knife, chop it into progressively smaller pieces.

The diagram below shows you where to cut to get just-intonated notes. The illustration shows a tube in the key of C - your tube pitch will probably be different. Use your sampler's pitch adjustment capabilities to fine-tune your samples.

Paper tube in the key of C

 

To build your scale make the cuts using the fractions listed above each note. For example, if your tube is 36" long, chop it at 32" (the length of the tube, or 36", times 8/9, or .8888 = 32") and it will dutifully sound a major 2nd above the fundamental. Continue chopping and sampling until you've got a full octave of notes, trim the pitches to perfection, then apply filters and effects as desired. Add a touch of chorus and reverb, and you'll be surprised at the musical richness and warmth you can achieve from a cardboard tube!

 

While you might not want to create your next CD with homemade instruments, combining found sounds with studio technology can lead you to interesting and exciting new textures that are completely unique.


Now pass me that wine glass and sledge hammer, please!