Bourdon (bell)
The bourdon is the heaviest of the bells that belong to a musical instrument, especially a chime or a carillon, and produces its lowest tone. The name derives from the French word for bumblebee.
Although carillons are by definition chromatic, the next bell up from the bourdon is traditionally a whole tone higher in pitch, leaving a semitone out of the instrument. Bells separated from the next higher note by more than two semitones are called sub-bourdons.
Function
The deep, resonant tone of a bourdon is use to mark hours, call to prayer, and solemnize major national or religious events like funerals, royal celebrations, or the end of wars, adding majesty and historical significance to bell towers and churches.Examples of Bourdon Bells
As an example, the largest bell of a carillon of 64 bells, the sixth largest bell hanging in the world, in the Southern Illinois town of Centralia, is identified as the 'bourdon.' It weighs and is tuned to G. In the Netherlands where carillons are native, the heaviest carillon is in Grote Kerk in Dordrecht.The biggest bell serving as bourdon of any carillon is the low C bell at Riverside Church, New York City. Cast in 1929 as part of the Rockefeller Carillon, it weighs and measures across.
The bourdon at St. Paul’s Cathedral in London, called Great Paul, weighs 16.7 tonnes. It is the largest bell ever cast in the British Isles. Great Paul is the second heaviest bell in the United Kingdom after the 25.7-tonne Olympic Bell, cast in the Netherlands for the 2012 London Games. As it is not a part of a harmonically-tuned set, the Olympic Bell is not considered a bourdon. Some cathedrals can have more than one bourdon bell. For example Notre-Dame de Paris has two bourdon bells, named Marie and Emmanuel which are hung in the south tower.