Secrets of the Woodwind Reed

One day in Egypt about 4000 years ago, someone blew across a slice of woody stem from a giant reed and discovered that the vibrating slice made a pleasant sound. Thus was born the class of musical instruments known as woodwinds.

Thus also was born the greatest headache woodwind players know, that of dealing with the fragile but inimitable reed. Even the best musician, now and then, will produce a disconcerting honk from an elderly or flawed reed lurking in the instrument's mouthpiece.

Despite thousands of years of complaining, musicians have pretty much accepted what nature gave. Science and technology have been applied toward finding an artificial and reliable substitute for natural reeds, but without real success. So far, the results have been more suitable for use by amateur players with a high tolerance for duck-like qualities in their tones.

But now many musicians are also scientists. Inevitably, somewhere the scientist-musicians would be tempted to combine interests to work on the problem of the tricky woodwind reed.

At Ohio State University, graduate student Donald J. Casadonte is working toward a doctorate in music. He's a clarinetist, but he's also a chemist. Chemist Casadonte analyzed the structure and other properties of woodwind reeds, as a first step toward improving their high high failure rate and short lifespan.

He found that the core tissue of giant reeds is organized in almost crystalline fashion, which is probably why it diffuses vibration so well and thus generates musical tones. Stiff cellulose forms the crystal lattice, while softer lignins and pectins fill the gaps and keep the reed tissue flexible while it oscillates during vibration.

Using infrared spectroscopy to compare old spent reeds with sound new ones, Casadonte found that spent reeds contain more carbon-oxygen double bonds. He doesn't know for sure why this happens or what it means, but suspects the player's saliva leaches pectins out of the reed to unmask the double bonds. The loss of pectins would explain why spent reeds cannot hold moisture as well as fresh ones do. This chemical degradation would make the cell walls thinner and more brittle, so the reed's higher vibrational frequencies would be enhanced. In effect, it would become more shrill.

A biological change appeared along with the chemical one. Casadonte found colonies of streptococcal bacteria living within the walls of the spent reeds' xylem tissue, the tiny tubes that conduct water in the living plant. The bacteria seem to thrive in their noisy habitat, because their colonies were dense enough to affect the vibrational qualities of the reed. The bacteria would damp the oscillations, enhancing lower frequencies in the reed and flattening its tone.

Even the physical structure was altered in the spent reed. Using infrared spectroscopy and X-ray diffraction techniques, Casadonte found evidence that reeds lose their crystal-like structure through the stress of repeated playing. This microcracking would eventually destroy the reed's capacity to produce pure tone. So far, Casadonte has come up with no cures for what ails the aging reed, except to support one belief common among woodwind players. Storing reeds in the refrigerator should slow both chemical and bacterial action, and so would prolong reed life.

While Casadonte continues experimenting with antimicrobial dips and repolymerization techniques, another graduate student is approaching the problem from its source. Clare Lawton is an oboe player who is working toward a doctorate in botany and engineering at the University of Reading in England. She has been studying and growing giant reed plants in an attempt to find out how the plants' environment affects the quality of the reeds. According to Science News, from which the foregoing information comes, Casadonte and Lawton are jointly carrying out the first comprehensive studies of the reed's physical, biological, and chemical properties. After thousands of years of suffering, woodwind players can take heart that someone is finally doing something about their problems.