A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an internal "clapper" or "uvula", an external hammer, or—in small bells—by a small loose sphere enclosed within the body of the bell (jingle bell).
Bells are usually cast from bell metal (a type of bronze) for its resonant properties, but can also be made from other hard materials. This depends on the function. Some small bells such as ornamental bells or cowbells can be made from cast or pressed metal, glass or ceramic, but large bells such as a church, clock and tower bells are normally cast from bell metal.
Bells intended to be heard over a wide area can range from a single bell hung in a turret or bell-gable, to a musical ensemble such as an English ring of bells, a carillon or a Russian zvon which are tuned to a common scale and installed in a bell tower. Many public or institutional buildings house bells, most commonly as clock bells to sound the hours and quarters.
Historically, bells have been associated with religious rites, and are still used to call communities together for religious services. Later, bells were made to commemorate important events or people and have been associated with the concepts of peace and freedom. The study of bells is called campanology.
Bell is a word common to the Low German dialects, cognate with Middle Low German belle and Dutch bel but not appearing among the other Germanic languages except the Icelandic bjalla which was a loanword from Old English. It is popularly but not certainly related to the former sense of to bell (bellan, 'to roar, to make a loud noise') which gave rise to bellow.
The earliest archaeological evidence of bells dates from the 3rd millennium BC, and is traced to the Yangshao culture of Neolithic China. Clapper-bells made of pottery have been found in several archaeological sites. The pottery bells later developed into metal bells.
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The course introduces the paradigm of quantum computation in an axiomatic way. We introduce the notion of quantum bit, gates, circuits and we treat the most important quantum algorithms. We also touch
Bell metal or bell bronze is an alloy used for making bells and related instruments, such as cymbals. It is a form of bronze with a higher tin content than most other bronzes, usually in approximately a 4:1 ratio of copper to tin (typically, 78% copper, 22% tin by mass). The higher tin content increases the rigidity of the metal, and increases the resonance. Historically, it was preferred for early cannons. Today, it also has industrial uses, being specified for valve bodies, piston rings, bearings, and bushings.
Change ringing is the art of ringing a set of tuned bells in a tightly controlled manner to produce precise variations in their successive striking sequences, known as "changes". This can be by method ringing in which the ringers commit to memory the rules for generating each change, or by call changes, where the ringers are instructed how to generate each change by instructions from a conductor. This creates a form of bell music which cannot be discerned as a conventional melody, but is a series of mathematical sequences.
A metallophone is any musical instrument in which the sound-producing body is a piece of metal (other than a metal string), such as tuned metal bars, tubes, rods, bowls, or plates. Most frequently the metal body is struck to produce sound, usually with a mallet, but may also be activated by friction, keyboard action, or other means. Metallophones have been used in music in Asia for thousands of years. There are several different types used in Balinese and Javanese gamelan ensembles, including the gendér, gangsa and saron.
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In 2012, a project proposed by local authorities aimed to revitalise, after a century of interruption, the use of Beijing’s Bell and Drum Towers and the social traditions associated with them. As a result, more than 100 households living in 66 traditional ...