Ben Hjertmann
Music Composition, Teaching, Recording, Instrument Building
PVC Memuks I & II
Want a fun weekend project that won't use your whole allowance? Build a Memuk!
The Memuk (as I call it, from membrane-duduk) is a membrane reed instrument. The body can be made or wood or bamboo, or PVC pipe and is similar to the body of a flute. The key difference is the mouthpiece and reed.
Aerophones (wind instruments, pipe organs, voices) work by cutting or interrupting an air stream. On a flute or organ pipe the air stream is cut by the relatively sharp edge of the instrument. Flutists aim the air over the edge of the mouthpiece.
Reed instruments are a subset of aerophones including clarinets, oboes, bassoons, saxophones, and reed organs. Take the clarinet as an example. As the clarinet player blows over the reed it vibrates and alternates between opening and closing the air path. That interruption occurs hundreds/thousands times per second and creates a waveform which is very similar to a square (a.k.a. pulse) wave (which alternates on...off...on...off, like digital clock). For this reason the timbre of a clarinet is very similar to square wave in having only (or mostly) odd harmonics present in its spectrum.
Membranes are normally heard in percussion instruments as drum heads, or as buzzy mirlitons on kazoos and balafons. But in this rare case, I am using a membrane as a reed. The air in blown in a smaller tube that is forced under a tight membrane of plastic shopping bag before exiting the instrument through it's body. The membrane vibrates, interrupting the air stream like a reed, but with a different timbre caused by it's shape, weight, material, etc.
The result is a buzzy, blaring wind instrument, possibly sounding similar to a duck call.
I was inspired by someone who made bagpipes in a similar fashion, later finding the incredible work of Bart Hopkin who himself has made many membrane reed instruments and who pointed to the practice separately arising by street artisans in Indonesia (who made them from old film canisters and balloons, I believe). His classic Musical Instrument Design book is worth every page of paper it was ever printed on. Highly recommended.
Memuk I, shown above has equally-spaced finger holes. Ignore my DIY inaccuracies. There are 8 holes, enough for all the fingers on both hands and no thumb holes on the back. (If you want a challenge, try to guess the scale it produces before checking the answer below. The pitch of the full pipe length, with all holes covered, is the F below middle C.)
Kathleen Schlessinger's The Greek Aulos, published almost 100 years ago, which was referenced in Harry Partch's Genesis of a Music, has been the subject of much debate then and now. Simply put, she contended that the ancient greek aulos (double-reed wind instrument) did not use the scales other historians and theorists contended but instead used equally-spaced finger holes. It seems to me that what she described (equally--spaced holes) on a wind instrument certainly did happen in Greece and elsewhere, but that doesn't mean it negates all the other well-documented Ancient Greek tunings and scales.
She mentions the intuitive, Occam's Razor element, which resonates with me. Don't you think some folks would have made equally-spaced holes on wind instruments? Yes. It's visually symmetrical, easy to measure and produce, it is easy on the hands/fingers, and to the eye it just makes sense. In fact, when I was 14 or so I bought a wooden flute from a street vendor in New Orleans, and played and recorded it years wondering what the heck the tuning was. It sounded both intuitive in many ways and just a little "wrong" in others. It wasn't until I started making these memuks and revisiting Schlessinger that I realized. It was six equally spaced holes!
When we have equal divisions of a scale length, like the equally-spaced holes in this example, we get a Utonal scale as Harry Parth would call it, meaning under-tonal rather than over-tonal. At first blush this might not seem right, but the visual symmetry is scale length, i.e. wavelength of vibration, and therefore inversely proportional to vibrating frequency. What looks equal sounds like exponentially higher intervals as we move up the scale. See my Rogue 48-Equal-Divisions-of-the-Scale-Length guitar for another example. Especially if you play guitar, you will be struck by how odd it looks to see equally spaced frets. We are used to frets shrinking as we move up in pitch, giving an "equal" sound to each interval (equal divisions of the octave, EDO).
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