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Sound Generator
A sound generator is a vibrating object which produces a sound. There are two main kinds of sound generators (thus, two main kinds of musical instruments). A full cycle of a sound wave will be described in each example which consists of initial normal conditions (no fluctuations in atmospheric pressure), an increase of air pressure, a subsequent decrease in air pressure which brings it back to normal, a decrease in air pressure (less pressure than initial conditions), and lastly, an increase which brings atmospheric pressure back to normal again. Therefore, the final conditions are the same as the initial, at-rest conditions. The first kind is simple and is called the vibrating or oscillating piston. Examples of this type of sound generator include the soundboard of a piano, the surfaces of drums and cymbals, the diaphragm of loudspeakers, etc. The forward movement of something through the atmosphere causes an immediate increase in air pressure (compression) or condensation in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musical Instrument
A musical instrument is a device created or adapted to make Music, musical sounds. In principle, any object that produces sound can be considered a musical instrument—it is through purpose that the object becomes a musical instrument. A person who plays a musical instrument is known as an ''#Instrumentalist, instrumentalist''. The history of musical instruments dates to the beginnings of human culture. Early musical instruments may have been used for rituals, such as a horn (music), horn to signal success on the hunt, or a drum in a religious ceremony. Cultures eventually developed composition and performance of melody, melodies for entertainment. Musical instruments evolved in step with changing applications and technologies. The exact date and specific origin of the first device considered a musical instrument, is widely disputed. The oldest object identified by scholars as a musical instrument, is Divje Babe flute, a simple flute, dated back 50,000–60,000 years. Many scho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piano
A piano is a keyboard instrument that produces sound when its keys are depressed, activating an Action (music), action mechanism where hammers strike String (music), strings. Modern pianos have a row of 88 black and white keys, tuned to a chromatic scale in equal temperament. A musician who specializes in piano is called a pianist. There are two main types of piano: the #Grand, grand piano and the #Upupright piano. The grand piano offers better sound and more precise key control, making it the preferred choice when space and budget allow. The grand piano is also considered a necessity in venues hosting skilled pianists. The upright piano is more commonly used because of its smaller size and lower cost. When a key is depressed, the strings inside are struck by felt-coated wooden hammers. The vibrations are transmitted through a Bridge (instrument), bridge to a Soundboard (music), soundboard that amplifies the sound by Coupling (physics), coupling the Sound, acoustic energy t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drum
The drum is a member of the percussion group of musical instruments. In the Hornbostel–Sachs classification system, it is a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a shell and struck, either directly with the player's hands, or with a percussion mallet, to produce sound. There is usually a resonant head on the underside of the drum. Other techniques have been used to cause drums to make sound, such as the thumb roll. Drums are the world's oldest and most ubiquitous musical instruments, and the basic design has remained virtually unchanged for thousands of years. Drums may be played individually, with the player using a single drum, and some drums such as the djembe are almost always played in this way. Others are normally played in a set of two or more, all played by one player, such as bongo drums and timpani. A number of different drums together with cymbals form the basic modern drum kit. Many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymbal
A cymbal is a common percussion instrument. Often used in pairs, cymbals consist of thin, normally round plates of various alloys. The majority of cymbals are of indefinite pitch, although small disc-shaped cymbals based on ancient designs sound a definite note (such as crotales). Cymbals are used in many ensembles ranging from the orchestra, percussion ensembles, jazz bands, heavy metal bands, and marching groups. Drum kits usually incorporate at least a crash, ride, or crash/ride, and a pair of hi-hat cymbals. A player of cymbals is known as a cymbalist. Etymology and names The word cymbal is derived from the Latin , which is the latinisation , which in turn derives . In orchestral scores, cymbals may be indicated by the French ; German , , , or ; Italian or ; and Spanish . Many of these derive from the word for plates. History Cymbals have existed since ancient times. Representations of cymbals may be found in reliefs and paintings from Armenian Highlands (7t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphragm (acoustics)
In the field of acoustics, a diaphragm is a transducer intended to inter-convert mechanical vibrations to sounds, or vice versa. It is commonly constructed of a thin membrane or sheet of various materials, suspended at its edges. The varying air pressure of sound waves imparts mechanical vibrations to the diaphragm which can then be converted to some other type of signal; examples of this type of diaphragm are found in microphones and the human eardrum. Conversely a diaphragm vibrated by a source of energy beats against the air, creating sound waves. Examples of this type of diaphragm are loudspeaker cones and earphone diaphragms and are found in air horns. Loudspeaker In an electrodynamic loudspeaker, a diaphragm is the thin, semi-rigid membrane attached to the voice coil, which moves in a magnetic gap, vibrating the diaphragm, and producing sound. It can also be called a cone, though not all speaker diaphragms are cone-shaped. Diaphragms are also found in headphones. Qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loudspeaker
A loudspeaker (commonly referred to as a speaker or, more fully, a speaker system) is a combination of one or more speaker drivers, an enclosure, and electrical connections (possibly including a crossover network). The speaker driver is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. The driver is a linear motor connected to a diaphragm, which transmits the motor's movement to produce sound by moving air. An audio signal, typically originating from a microphone, recording, or radio broadcast, is electronically amplified to a power level sufficient to drive the motor, reproducing the sound corresponding to the original unamplified signal. This process functions as the inverse of a microphone. In fact, the ''dynamic speaker'' driver—the most common type—shares the same basic configuration as a dynamic microphone, which operates in reverse as a generator. The dynamic speaker was invented in 1925 by Edward W. Kellogg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compression (physical)
In mechanics, compression is the application of balanced inward ("pushing") forces to different points on a material or structure, that is, forces with no net sum or torque directed so as to reduce its size in one or more directions.Ferdinand Pierre Beer, Elwood Russell Johnston, John T. DeWolf (1992), "Mechanics of Materials". (Book) McGraw-Hill Professional, It is contrasted with tension or traction, the application of balanced outward ("pulling") forces; and with shearing forces, directed so as to displace layers of the material parallel to each other. The compressive strength of materials and structures is an important engineering consideration. In uniaxial compression, the forces are directed along one direction only, so that they act towards decreasing the object's length along that direction. The compressive forces may also be applied in multiple directions; for example inwards along the edges of a plate or all over the side surface of a cylinder, so as to reduce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rarefaction
Rarefaction is the reduction of an item's density, the opposite of compression. Like compression, which can travel in waves (sound waves, for instance), rarefaction waves also exist in nature. A common rarefaction wave is the area of low relative pressure following a shock wave (see picture). Rarefaction waves expand with time (much like sea waves spread out as they reach a beach); in most cases rarefaction waves keep the same overall profile ('shape') at all times throughout the wave's movement: it is a ''self-similar expansion''. Each part of the wave travels at the local speed of sound, in the local medium. This expansion behaviour contrasts with that of pressure increases, which gets narrower with time until they steepen into shock waves. Physical examples A natural example of rarefaction occurs in the layers of Earth's atmosphere. Because the atmosphere has mass, most atmospheric matter is nearer to the Earth due to the Earth's gravitation In physics, gravity ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Instrument
A wind instrument is a musical instrument that contains some type of resonator (usually a tube) in which a column of air is set into vibration by the player blowing into (or over) a mouthpiece set at or near the end of the resonator. The pitch of the vibration is determined by the length of the tube and by manual modifications of the effective length of the vibrating column of air. In the case of some wind instruments, sound is produced by blowing through a reed; others require buzzing into a metal mouthpiece, while yet others require the player to blow into a hole at an edge, which splits the air column and creates the sound. Methods for obtaining different notes * Using different air columns for different tones, such as in the pan flute. These instruments can play several notes at once. * Changing the length of the vibrating air column by changing the length of the tube through engaging valves ''(see rotary valve, piston valve)'' which route the air through additional tubing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trumpet
The trumpet is a brass instrument commonly used in classical and jazz musical ensemble, ensembles. The trumpet group ranges from the piccolo trumpet—with the highest Register (music), register in the brass family—to the bass trumpet, pitched one octave below the standard B or C trumpet. Trumpet-like instruments have historically been used as signaling devices in battle or hunting, with examples dating back to the 2nd Millenium BC. They began to be used as musical instruments only in the late 14th or early 15th century. Trumpets are used in art music styles, appearing in orchestras, concert bands, chamber music groups, and jazz ensembles. They are also common in popular music and are generally included in school bands. Sound is produced by vibrating the lips in a mouthpiece, which starts a standing wave in the air column of the instrument. Since the late 15th century, trumpets have primarily been constructed of brass tubing, usually bent twice into a rounded rectangular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siren (noisemaker)
A siren is a noise-making warning device. There are two general types: mechanical sirens and electronic sirens. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire engines. Many fire sirens (used for summoning volunteer firefighters) serve double duty as tornado or civil defense sirens, alerting an entire community of impending danger. Most fire sirens are either mounted on the roof of a fire station or on a pole next to the fire station. Fire sirens can also be mounted on or near government buildings, on tall structures such as water towers, as well as in systems where several sirens are distributed around a town for better sound coverage. Most fire sirens are single tone and mechanically driven by electric motors with a rotor attached to the shaft. Some newer sirens are Electronics, electronically driven speakers. Fire sirens are often cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ (music)
Carol Williams performing at the West_Point_Cadet_Chapel.html" ;"title="United States Military Academy West Point Cadet Chapel">United States Military Academy West Point Cadet Chapel. In music, the organ is a keyboard instrument of one or more Pipe organ, pipe divisions or other means (generally woodwind or electronic musical instrument, electric) for producing tones. The organs have usually two or three, sometimes up to five or more, manuals for playing with the hands and a pedalboard for playing with the feet. With the use of registers, several groups of pipes can be connected to one manual. The organ has been used in various musical settings, particularly in classical music. Music written specifically for the organ is common from the Renaissance to the present day. Pipe organs, the most traditional type, operate by forcing air through pipes of varying sizes and materials, each producing a different pitch and tone. These instruments are commonly found in churches and co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
