Alphorn players, Bavaria, Germany

The Alpine sound of Oktoberfest. Oktoberfest, Germany

As Oktoberfest opens today, visitors arriving in Bavaria, Germany, may hear a sound even older than the famous festival itself: the deep, resonant voice of the alphorn. This traditional Alpine instrument is closely linked to Bavaria, Austria and Switzerland, where it once helped shepherds communicate across mountain valleys.

An alphorn is a long wooden wind instrument, typically about 3.5 metres long. Usually crafted from spruce, it has no valves, keys or finger holes. Instead, musicians create different notes by controlling their breath and lip tension through a wooden mouthpiece.

Despite its name, Oktoberfest starts in mid-to-late September to take advantage of warmer, milder weather. The celebration began in 1810 as a festival marking the marriage of Crown Prince Ludwig and Princess Therese, with a horse race at its centre. Today, locals often call it the Wiesn, after its Theresienwiese grounds. With millions of visitors, traditional music and Bavarian culture remain at the heart of the world's largest Volksfest.