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impression that there are no open questions. One important area that is still ripe for investigation concerns the motion of the lips during play and how the instrument interacts with them. There has been significant work in this area, but there is still much we do not understand (e.g., Yoshikawa, 1995; Stevenson et al., 2009; Boutin et al., 2015). Similarly, almost all brass players firmly believe that the effects of the vibrations of the instrument have a significant effect on the sound. This has been shown to be true in the case of bell vi- brations (Moore et al., 2005) and a theory has been proposed to explain the effect (Kausel et al., 2015; Moore et al., 2015), but it is not clear that vibrations of other parts of the instru- ment affect the sound.
There are many things that musicians think are important but about which many scientists are skeptical. For exam- ple, a short discussion with almost any skilled brass player will quickly elicit an opinion on the importance of the dc air flow. Air must pass through the instrument during play, but this is just a by-product of the buzzing lips. By placing a rubber diaphragm between the mouthpiece and tubing, it can be shown that the airflow is not needed to produce the sound. All that is required is for the pressure oscillations to be propagated down the tube. However, almost all musicians believe the flow of the air is critical to the sound. Many sci- entists are less certain.
We understand the basic physics of how brass instruments produce sound and recognize that there are still interesting questions to pursue; however, it is important to remember that brasswind instruments are not scientific instruments. They are played by artists and their value lies in their abil- ity to help a human make music. The ability of these instru- ments to make music motivates the research, but those of us who study the physics of musical instruments agree that mu- sic should be enjoyed without thought to the complicated acoustics that produces the sound. We save those thoughts for after the concert.
Acknowledgments
I am indebted to Dr. Brian Shook, Vincent Bach Perform- ing Artist and Clinician and Associate Professor of Music at Lamar University, who generously provided all of the sound files (www.brianshook.com).
Biosketch
Thomas Moore is the Archibald Gran- ville Bush Professor of Natural Science at Rollins College, Winter Park, FL. His current research interests are under- standing the physics involved in produc- ing musical sound and the development of optical methods for acoustical analy- sis. He is a retired Army officer, was the
Carnegie Foundation for the Advancement of Teaching 2013 Florida Professor of the Year, and is a Fellow of the Acousti- cal Society of America.
References
Atema, J. (2014). Musical origins and the stone age evolution of flutes. Acoustics Today 10, 26-34.
Baines, A. (1976). Brass Instruments: Their History and Development. Faber and Faber, London. Dover reprint, 2012.
Boutin, H., Fletcher, N., Smith, J., and Wolfe, J. (2015). Relationship be- tween pressure, flow, lip motion, and upstream and downstream imped- ances for the trombone. The Journal of the Acoustical Society of America 137, 1195-1209. doi:10.1121/1.4908236.
Campbell, M., Greated, C., and Myers, A. (2006). Musical Instruments: His- tory, Technology and Performance of Instruments of Western Music. Oxford University Press, New York.
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