A beautiful installation entitled Fanfare can be visited at the Metropolitan Museum of Art in New York (the MET). In it, a humble conch is situated in the center of an imaginary explosion that gives rise to all the brass instruments in history. The conch is the starting point. Around it the forms and materials diverge, twist, branch … but they all have a common origin. The title of the installation refers to a musical form, of short duration and bombastic sonority, which used to be used to announce the arrival of some important personality. The fanfares were performed by trumpets or other brass instruments, with the occasional accompaniment of percussion. Its name comes from the Mozarabic farfar and probably shares its root with the word boastful . Since then, the brass wind chime and trumpets in particular have been associated with royalty and power, with military marches, pomp and circumstance. The ultimate reason for this association is probably one of its most outstanding acoustic properties. Like conches, the other brass instruments stand out for their great sound power, which makes them ideal for communicating signals on the battlefield.
In the musical field, this great sound has also marked the use of these instruments. There are even jokes about it. According to a quote attributed to Richard Strauss (or alternatively Richard Wagner), a good conductor should "never look at the trombones: he only encourages them." The trombone is, in fact, the instrument with the greatest sonic power in the orchestra, with peaks reaching 115 decibels. Such a sound can damage your hearing within 30 seconds of exposure: it is louder than that of an electric saw or an ambulance siren. The Strauss quote, on the other hand, is slightly apocryphal. But only slightly. It is an exaggeration based on the fourth of his " 10 golden rules for the young conductor ". There Strauss recommends: "never look encouragingly at the metal wind, except with a slight glance to give some important indication." On the other hand, it also does not appear that Strauss directed " encouraging glances " to any member of the orchestra at all.
Due to their power and brilliance, the timbre of these instruments, especially when played in a dynamic forte has often also been described as "metallic" or, in English, "brassy". However, this sound has nothing to do with the material with which they are made. It is paradoxical that material names are always used to qualify wind instruments precisely the instruments in which the material has less relevance ! Several studies 1 2 3 show that the characteristic sound brassy is actually due to the amplitude of the sound waves, which causes non-linear effects  in the propagation of sound within the tube. These effects give rise to shock waves (a variation in pressure that moves faster than the sound itself in that medium) and cause the sound energy to concentrate on higher frequencies where our hearing is more sensitive. The longer the tube, the more likely this phenomenon is to occur, which explains why the trombone, at almost three meters in length, is especially “brassy”.
The result is a bright and rough sound, something strident even. Thanks to her, brass instruments tend to stand out above the others in the orchestra. It's not just about decibels – its “metallic” timbre helps that too. That's probably why the same Richard Strauss who avoided looking at the trombones also recommends young conductors: "If you think the brass instruments aren't playing enough, turn the volume down a degree or two more."
1 Beauchamp, J. (1980) '' Analysis of simultaneous mouthpiece and output waveforms, 'Audio Engineering Society preprint No. 1626.
2 Hirschberg, A., Gilbert, J., Msallam, R., Wijnands, APJ (nineteen ninety six). "Shock waves in trombones," J. Acoust. Soc. Am. 99, 1754-1758.
3 Rendón, Pablo & Orduña-Bustamante, Felipe & Narezo Guzman, Daniela & Pérez-López, Antonio & Sorrentini, Jacques. (2010). Nonlinear progressive waves in a slide trombone resonator. The Journal of the Acoustical Society of America. 127. 1096-103. 10.1121 / 1.3277221.
About the author: Almudena M. Castro is a pianist, graduated in fine arts, graduated in physics and science popularizer