August 10, 2007
Have you ever wondered just how your favorite musical instrument actually produces such melodic sounds? This summer, as part of the Student-Faculty Summer Scholarship Program, Rollins College junior Laurie Stephey and Professor of Physics Thomas Moore researched just how the banjo, a seemingly simple instrument, produces sounds.
“As part of our ongoing research on the physics of musical instruments, we have been investigating the physics of the banjo in an attempt to understand why it sounds as it does,” Moore said. “To date, there has been little work on the science of this uniquely American instrument, which is not surprising considering the complexity of the many interacting elements.”
Stephey began working on the project in 2005 the summer before her first year at Rollins. She had already decided she would be a physics major, and wanted to get started with research right away. The physics department has been studying various instruments and how they work, including the piano, African drums and the bass guitar. The physics of the five-string banjo project had already been started, and Stephey picked it up and kept working on it.
“Banjo players talk about a black magic when tuning their instruments because they don’t know how or why it works, just that if they do certain things it will work,” Moore said.
Stephey and Moore measured how the instrument works—how the head vibrates and how the strings vibrate. After three years of work, the experimental part of the project is complete and Stephey is now analyzing the data and beginning to form a scientific paper on her findings. “Working with the banjo has been a great project,” Moore said. “We originally chose the instrument because we thought it seemed so simple, but it surprisingly turned out to be a lot of work.”
It took two years for the team just to come up with the experimental part of the project—how they were going to test the vibrations of the instrument and measure them. They have built a device that can observe motion on a very small scale in real time. “You can literally see things move because of the vibrations caused by speaking,” Moore said. The team has also been assisted by a visiting collegue from England and Donald Griffin, a Rollins professor of physics who specializes in quantum mechanics. Griffin is still working on the complicated equations the data from the banjo has produced.
Over the summer, Stephey spent two months in the lab five days a week for eight hours a day. She would come in early in the morning and late at night because she had to start a data set and then come back in to check on it. Stephey had her own area in the lab and all the experiments were computer controlled, but she had to monitor and pull data and analyze the findings. She also shared the equipment with other students. “She has really put in some hours on this project,” Moore said. “Laurie is so dedicated, and she knew that she wanted to do this, so we have been lucky that all our hard work has brought results.”
The team is now finished with the experiment stage and they have their data. Stephey has begun to work on a paper to submit to the The Journal of the Acoustical Society of America. She will present the paper next summer at a professional conference in Paris. “There is a community out there who is interested in this kind of research,” Moore said. “We aren’t the only ones studying the banjo, others have tried and failed because they didn’t know how to measure the vibrations.”
The physics department has recently received a grant from the National Science Foundation to combine their research of the motion of musical instruments with a high speed camera so they can observe small motions at very high speeds. This will allow them to take their research of the banjo to another level that Stephey may continue with for her honors thesis.
But while Stephey has been investigating the banjo for two years and has performed some of the first experiments that have opened the door into understanding how the instrument works, she does not play a banjo and has never had the opportunity to discuss her results with a professional-level player. It has become clear that it is time for music and science to sit down at the same table and talk.
Therefore, Rollins has arranged for Jeff Scroggins, two-time winner of the National Bluegrass Banjo Championship, to come to the College as a Thomas P. Johnson visiting scholar to specifically discuss the banjo and banjo playing with students. Scroggins plays professionally in several bluegrass bands, as well as being a regular solo and ensemble performer. In 1999 his band, The Big Twang, won the prestigious Rocky Grass Band Championship. He has performed and recorded with Steve Kaufman, Marty Stewart, The Dixie Chicks and many other well-known artists.
Scroggins will be accompanied by Dr. Robert A. Fisher, physicist and guitar player, who will participate in both the musical and scientific roles. Scroggins and Fisher will spend October 22 with students and then will present an evening concert of blue grass music, which will be open to the public.
“One of the advantages of our study of the banjo is that this research uses all the kinds of physics that we teach here,” Moore said. “This is getting to experience world class science first hand.”
Student Perspective: Figuring Out the Physics of the Five-String Banjo
Back to Students and Faculty Come Together for Research
