Silicon for a Swiss national symbol - the alphorn 

Published by Angst+Pfister on February 2023

Who would have thought it? When the far-reaching sound of an alphorn echoes between magnificent mountain peaks of Switzerland, Angst+Pfister is singing along. The traditional craftsmanship of Bruno Cattaneo, maker of high-quality alphorns, does not forgo O-rings to seal the instrument's three wooden pipe sections. An enthusiastic alphorn player and the Angst+Pfister agent from Italian-speaking Switzerland suspected that this could be done even better. 

Legend has it that the alphorn was a gift from the spirits: One night, high above Lake Brienz, three figures appeared to the young herdsman Res. They offered him a choice of red, green, or white milk whey. Red whey would bestow upon him miraculous powers, and green one would make the most beautiful Alps his own. However, the herdsman chose the honey-sweet, white whey. And after consuming it, his hearth flared then subsided, and by the fire lay an alphorn. He blew the horn and paused until the sound echoed back to him like the voices of spirits. In the valley below, the people thought the mountains had begun to sing. That is the myth. In any event, the spirits left behind the first alphorn, in those times without  O-rings from APSOparts - Angst+Pfister's online shop - between the connected wooden pipes. 

Without a doubt, it is the most iconic symbol of Switzerland - ahead of fondue, edelweiss, pocketknives, or clocks. Alphorn is home. Yet at one time, the alphorn fell into disrepute and became known as the begging horn as it was associated with impoverished herdsmen playing it to beg for money. It came back into fashion in the 19th century with the romantic transfiguration of the Alps, the beginnings of tourism, and the celebration of tradition at the first national herdsmen festivals, the Unspunnen festivals near Interlaken, which still take place regularly today.  


O-rings for the highest standards of craftsmanship 

How the first Angst+Pfister O-ring became an integral part of Switzerland’s foremost heritage treasure is for the engineers as uncertain as the mythical origins of the instrument. One thing was for sure: An intermediary ordered O-rings for Bruno Cattaneo, the alphorn maker of Graubünden, from the APSOparts shop. When he dropped them off, they would drink a glass of Merlot and play the alphorn together. That is what Urs Arnold - a keen alphorn player and customer of Bruno Cattaneo - knew. He is on first-name terms with Francesco Brunone, the long-standing Angst+Pfister agent for Italian-speaking Switzerland. "I was amazed when I heard from my colleagues that our rubber rings are incorporated the alphorn," said Francesco Brunone. 

Bruno Cattaneo is not just anyone. Urs Arnold calls the company the Stradivarius of alphorn makers. He had splashed out on an alphorn about five years ago - one with the typical voluminous timbre for which the company is renowned. A really good one costs between 3,500 and 6,000 francs. Today, there are also telescopic-type carbon horns. "They are better suited to airplanes," says Urs Arnold. At Bruno Cattaneo’s workshop, everything is pure craftsmanship using predominantly traditional techniques - without the help of computer-controlled machines.  

The wood and the seal are vital. 

The main protagonist in alphorns is the wood. Bruno Cattaneo selects the wood for his alphorns together with foresters in the mountains of the Swiss canton of Graubünden. Only wood with the right resonance has the quality to transmit vibrations in such a way that the alphorn sounds good. It requires centuries-old spruce trees growing at an altitude of between 1400 and 1600 meters. There, the climate causes the wood to grow slowly and evenly, with annual rings homogeneous enough to become the compact and sonorous base material of the instruments. The typical curvature of the horn requires trunks that have grown on steep slopes.  

Almost as important as the wood are the seals - today's standard alphorns consist of three parts. It is crucial that the sections fit very tightly into each other. No air is allowed to get out," says Urs Arnold. If the parts do not fit perfectly together, the pitch or sound quality will be adversely affected. There are five notches in Bruno Cattaneo's connectors, into each of which an O-ring is placed. "The seals have to ensure that the vibrating air blasts do not escape from the long tube - except through the sounding cup at the end. Simultaneously they have to allow the sections of the instrument to slide smoothly into each other," says Bruno Cattaneo.   

Silicone rather than lubrication? 

"Players use Vaseline or milking grease to make it easier to push the alphorn sections together," explains Urs Arnold. The disadvantage of this method is that the lubrication also collects dirt. This gave Francesco Brunone an idea: "The O-rings in the alphorns are conventional black NBR rings. Silicon rings would probably make it possible to fit the sections together without requiring lubricant."            

The concept meanwhile reached the ears of Bruno Cattaneo's workshop, and silicon rings were ordered from Angst+Pfister. "The first tests have been very promising," Bruno Cattaneo is pleased to report. Assembly and closure had worked very well for the smaller seals and were reflected in the sound. "We are still experimenting with the diameter of the larger rings. For the smaller ones, we have already begun a long-term trial on several alphorns in our group." If this test is also successful, the new seals will be used in the alphorns so that the mountains sing even more beautifully in the future. 


The collaboration between Urs Arnold, Francesco Brunone, and Angst+Pfister highlights a commitment to enhancing the instrument's quality and playability. Through experimentation with silicone o-rings, there's a tangible excitement about the potential improvements in sound and ease of assembly, promising a future where the mountains' melodies resonate even more beautifully.

This corporation is a testament to the dedication of craftsmen like Bruno Cattaneo to preserve and elevate Switzerland's cultural heritage while embracing advancements in materials and techniques.

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