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The Function of the Player's Lips

As long ago as 1830 Wilhelm Weber carried out experiments on the action of organ reeds which led him to a correct theory for the effect of a yielding termination (the reed, that is) on the end of a column of air.2 In the present context this means that Weber provides us with an understanding of how the player's fleshy lips form a yielding closure to the mouthpiece, in addition to their special function as a rapidly acting flow-control valve. Hermann Helmholtz provided the next advance. In 1877 he added an appendix to the fourth German edition of his classic work, Sensations of Tone, which provides a brief but complete analysis of the basic mechanism whereby a reed, or the player's lips, responds to the acoustic pressure variations within the mouthpiece to control the air admitted from the player's lungs into his instrument.3 The best account of the Weber-Helmholtz analysis and its musical consequences was made by Henri Bouasse in his book, Instruments à vent, the two volumes of which appeared in 1929 and 1930. These volumes contain what still constitutes one of the most thorough accounts of wind instrument acoustics dealing with the brasses and the orchestral woodwinds, as well as the flute and reed organ pipes. Bouasse has left us with a gold mine of mathematical analysis along with accounts of careful experiments done in collaboration with H. Fouché or selected from the writings of earlier researchers. The non-technical reader can find an account of many of these matters in my book, Horns, Strings and Harmony,4 and in more detail in a recent article in Scientific American magazine.5

Trumpet Acoustics
Acoustical Preliminaries
The "Water Trumpet"-- An Analog to What Happens inside a Trumpet
The Function of the Player's Lips
The Function of the Pipe and Bell--Inside the Air Column
The Cooperation Needed for Musical Results
The Baroque Trumpet
The 'Internal' Spectrum of the Modern Trumpet
The 'Internal' Spectrum of the Baroque Trumpet
Relation of Internal to External Tone Color Spectrum
The Menke Trumpet
The Problem of Clean Attack
Mahillon in Retrospect
Conclusion
Bibliographic Notes