Ear of the Beholder--Part 2

So the students and I faced an ongoing struggle that is created when an objective scientist is trying to reach a group of subjective musicians. They often were skeptical of the scientific material in our text. Luckily, I was teaching a laboratory course, so I was able to introduce them to the experimental method, wherein they could prove to themselves the truth of the physical properties of their musical instruments.

I ran into stiff resistance when we studied acoustic properties of their instruments that sometimes countered the message they were given by the conservatory staff. For example, brass players had been taught that the specific metal alloy of their instrument had a defining role in its sound quality. Woodwind players had been taught that the quality of sound they made was strongly dependent on whether the clarinet or oboe was made of an exotic tropical wood or a good grade of plastic. In fact, tests have shown that the material of a musical instrument has minimal influence on its tone. It’s much more a function of the shape of the instrument’s inner air column and the qualities of the player’s embouchure (the way that the player applies her lips and tongue to the mouthpiece). Unfortunately, there are no unequivocal tests that we could conduct in a college lab that would unambiguously evaluate sound quality, so our credibility gap in that area remained.

I did manage to come up with one lab test that was able to refute one of their main beliefs. We were studying in our text the subject of what distinguishes the sound of one musical instrument from another. How does one tell the sound of a violin from a trombone, or a clarinet from a trumpet? The answer seems obvious to anyone who has listened to music. They are very distinctive. The author of our text described that the main distinguishing characteristic was not the nature of the tone of an instrument, but unique qualities that can be heard at the very beginning and ending of a note. It’s not the steady tone that is distinctive, it’s the transient sounds on each end of a note.

This result seems to go against the experience of anyone who is at all familiar with music. As expected, the students were very resistant to the message. So, together we designed an experiment to test it out in our next lab. They all brought their instruments—clarinet, trombone, flute, trumpet, guitar, violin, cello, French horn, oboe, saxophone, and even voice. We picked a note that every instrument could play at the same pitch—I think it was A above middle C.

Each student stepped to the microphone and played that note for about 30 seconds, as we recorded it on tape. We chose one student to go alone into another room and erase the first and last couple of seconds from each recording—leaving only the steady, middle part of the note. He then scrambled the order of the recordings—making his secret notes as to the new sequence.

He then came back into the lab and played the 20-second samples, as the students listened and made their choices of which instrument made which tone. It surprised me at how similar the notes sounded, as I watched looks of consternation and perplexity cross their faces. They were clearly taken aback. When all tones had been played, I asked them if they wanted to listen to them again, before making their final choices. All heads nodded approvingly, brows knitted.

At the end of the second round, we tallied the scores. It was quite astonishing: on average, the class had correctly identified only one-third of the instruments. Their response to the test was somewhere between being awestruck and disbelief. I don’t think they became instant converts to the scientific principle, but it sure made an impression on them. They had proved to themselves something about the physics of sound that countered their subjective experience. For the rest of the course, the communication gap between us seemed a bit narrower.

Ear of the Beholder--Part 1

For centuries, violinists have sung paeans to the accomplishments of the Cremona master violinmakers—especially Antonio Stradivari and Giuseppe Guarneri del Gesu. These two geniuses constructed instruments that are regarded as the zenith of their art. The violinists of today—at least those of appropriate means—will pay several million dollars for an original 300 year-old Strad or Guarneri violin. Do these instruments warrant such a price?

For many years, scientists have studied these venerable violins, trying to figure out what makes their sound so special… or is it special? Is it the varnish they used? Is it the wood? Does an instrument improve with age, as its body absorbs the vibrations of its own music? Was there some kind of magic that the masters had that is a lost art? Various tests have been made, but none so far has shed any real light on the quandary. The owners of the surviving violins are not open to someone dissecting their precious treasures, so the years pass, without an answer. In the meantime, musicians remain convinced that there is something transcendent about a Cremona violin that escapes today’s artisans.

Finally, last year a French acoustician partnered with an American violin maker to design an experiment that shed some new light on the issue. At an international violin competition in Indianapolis, they recruited 21 professional violin players to participate in the experiment. (Previous listening tests had never used professional players, so they were open to criticism that lesser talented players were not adequate for the job.) The researchers were able to talk owners of three precious old violins to allow their instruments to be used: two were Strads and one was a Guarneri. They added three new, high-quality violins to the package, so the players had a total of six instruments to compare.

The tests were conducted in a darkened room and the musicians wore dark goggles, so they could not see which instrument they were playing. Two different kinds of tests were conducted: (1) each player was handed two random violins (one old and one new) and was asked to choose the better one, and (2) each player was allowed to play every one of the six violins and pick the one that they’d like to take home.

The results were startling. In the first test, there was no clear winner of the six violins, but there was one clear loser: one of the precious Strads. For the second test, only one-third of the 21 professionals chose an old violin as the best. In fact, two-thirds of them preferred the sound of a new violin. The musicians were flabbergasted at the results. Before the test was conducted, they were convinced that they could readily tell the difference between an old jewel and a new violin. Some of them expressed the feeling that the test was the experience of a lifetime.

So what’s the message here? It seems to be obvious that some kind of mystique surrounds the preference for the old masters. Like similar findings in blind tastings of wine, people can delude themselves about the superiority of expensive items. When it comes down to an objective test, when inherent biases are avoided, maybe there is nothing so special about those high-priced violins. Sure, those old masters were pioneers in making superb violins, but maybe today’s makers are doing as good a job.

This comparison fascinated me, because it is similar to a test that I conducted a couple of decades ago, when I taught a course on musical acoustics at the local university. I loved teaching this course, since it brought together two of my passions: physics (which I was also teaching at the time) and music. The basic focus of the course was the study of how musical instruments make their sounds. The course was a challenge for both the students and me. Most of them were music majors trying to brave their way through an intimidating science course (foreign territory to them!) and I was struggling to make the material comprehensible to non-science types.

My biggest obstacle was to try to convince the music majors to accept scientific truths about their instruments. These truths had been arrived at over many years by conducting experiments whose results provide insight into how Mother Nature works. In science, one accepts the validity of propositions only after repeatable experiments end with the same results. Anyone can conduct these experiments—whether neophyte student or experienced scientist. It’s a democratic process. One is delving into the facts of how the physical world behaves, and these facts are independent of any human perception.

The topics that music students study, however, are quite subjective. Their perceptions and emotions play a central role in how they discern the quality of a musical performance. It’s in the ear of the beholder. It’s what one senses or learns to appreciate over time, as one’s ear becomes educated. There is no scientific instrument, for example, that can tell which of two flute players is the better performer. Music students learn to accept the word of their professors as truth, even the gospel. They rely on the reputation or talent of their teachers. Faith and belief can play a large role in their discriminating tastes.

More on musical instrument sound quality next time…