Donald J. Leslie
Donald James Leslie (April 13, 1911 – September 2, 2004) created and manufactured the Leslie speaker that refined the sound of the Hammond organ and helped popularize electronic music. Leslie experimented with devices to, in his words, improve the sound of the Hammond organ, based on experience he gathered from other jobs, including repairing radios and one at the Naval Research Laboratory in Washington, D.C., during World War II. Donald Leslie was impressed with the sound of a Hammond organ in a concert hall but less enthused with it in a confined space. There, the sound had no resonance, and the pure electronic oscillators sounded "dull, shrill, and still" to Leslie's ear. To remedy this problem, in 1937 he invented a speaker which rotates inside its cabinet, producing a Doppler effect which modulates the sound. To some extent this imitates the resonance of the organ in a large auditorium by projecting it 360 degrees. This device was eventually one of over 50 patents he owned ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Danville, Illinois
Danville is a city in and the county seat of Vermilion County, Illinois. As of the 2010 census, its population was 33,027. As of 2019, the population was an estimated 30,479. History The area that is now Danville was once home to the Miami, Kickapoo, and Potawatomi tribes of Native Americans. Danville was founded in 1827 on of land donated by Guy W. Smith and donated by Dan W. Beckwith. The sale of lots was set for April 10, 1827 and advertised in newspapers in Indianapolis, Indiana and the state capital of Vandalia. The first post office was established in May of the same year in the house of Amos Williams, organizer of Vermilion and Edgar Counties and a prominent Danville citizen. Williams and Beckwith drew up the first plat map; the city was named after Dan Beckwith at Williams' suggestion, although Beckwith suggested the names "Williamsburg" and "Williamstown". Beckwith was born in Pennsylvania in 1795 and moved to Indiana as a young man; in 1819 he accompanied the first ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Altadena, California
Altadena () ("Alta", Spanish for "Upper", and "dena" from Pasadena) is an unincorporated area and census-designated place in the Verdugo Mountains region of Los Angeles County, California, approximately 14 miles (23 km) from the downtown Los Angeles Civic Center, and directly north of the city of Pasadena, California. The population was 42,777 at the 2010 census, up from 42,610 at the 2000 census. Etymology The name Altadena derives from the Spanish ''alta'', meaning "upper", and ''dena'' from Pasadena; the area is adjacent to, but at a higher elevation than, Pasadena.Manning, Mike. The word Altadena was first used by Byron Clark, who coined it for his nursery located south of present-day Woodbury on the west side of town. When he moved his nursery to Linda Vista, he agreed to let the Woodburys take the name for their new subdivision.ALTADENA, CALIFORNIA: an abbreviated history for the internet"Altadena Town Council Retrieved on March 18, 2007. History In the mid-1860s ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Leslie Speaker
The Leslie speaker is a combined amplifier and loudspeaker that projects the signal from an electric or electronic instrument and modifies the sound by rotating a baffle chamber ("drum") in front of the loudspeakers. A similar effect is provided by a rotating system of horns in front of the treble driver. It is most commonly associated with the Hammond organ, though it was later used for the electric guitar and other instruments. A typical Leslie speaker contains an amplifier, a treble horn and a bass speaker—though specific components depend upon the model. A musician controls the Leslie speaker by either an external switch or pedal that alternates between a slow and fast speed setting, known as "chorale" and "tremolo". The speaker is named after its inventor, Donald Leslie, who began working in the late 1930s to get a speaker for a Hammond organ that better emulated a pipe or theatre organ, and discovered that baffles rotating along the axis of the speaker cone gave the best ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hammond Organ
The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated sound by creating an electric current from rotating a metal tonewheel near an electromagnetic pickup, and then strengthening the signal with an amplifier to drive a speaker cabinet. The organ is commonly used with the Leslie speaker. Around two million Hammond organs have been manufactured. The organ was originally marketed by the Hammond Organ Company to churches as a lower-cost alternative to the wind-driven pipe organ, or instead of a piano. It quickly became popular with professional jazz musicians in organ trios—small groups centered on the Hammond organ. Jazz club owners found that organ trios were cheaper than hiring a big band. Jimmy Smith's use of the Hammond B-3, with its additional harmonic percussion feature, inspired a g ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraf ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Naval Research Laboratory
The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. It was founded in 1923 and conducts basic scientific research, applied research, technological development and prototyping. The laboratory's specialties include plasma physics, space physics, materials science, and tactical electronic warfare. NRL is one of the first US government scientific R&D laboratories, having opened in 1923 at the instigation of Thomas Edison, and is currently under the Office of Naval Research. As of 2016, NRL was a Navy Working Capital Fund activity, which means it is not a line-item in the US Federal Budget. Instead of direct funding from Congress, all costs, including overhead, were recovered through sponsor-funded research projects. NRL's research expenditures were approximately $1 billion per year. Research The Naval Research Laboratory conducts a wide variety of basic research and applied r ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Doppler Effect
The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer. Compared to the emitted frequency, the received frequency is higher during the approach, identical at the instant of passing by, and lower during the recession. The reason for the Doppler effect is that when the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the crest of the previous wave. Therefore, each wave takes slightly less time to reach the observer than the previous wave. Hence, the time between the arrivals of successive wave crests at the observer is reduced, causing an increa ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Laurens Hammond
Laurens Hammond (January 11, 1895 – July 1, 1973), was an American engineer and inventor. His inventions include the Hammond organ, the Hammond clock, and the world's first polyphonic musical synthesizer, the Novachord. Youth Laurens Hammond was born in Evanston, Illinois, on January 11, 1895 to William Andrew and Idea Louise Strong Hammond. Laurens showed his great technical prowess from an early age. His father, William, took his own life in January 1897, ostensibly due to failure of the First National Bank of Illinois, which he had founded. Upon her husband's death, Idea, who was an artist, relocated to France with Laurens to further her studies, and the family spent the next eleven years in France and Germany. Early inventions When the family returned to Evanston in 1909, Laurens, then 14, was fluent in French and German. While in Europe, he had already designed a system for automatic transmission for automobiles. At his mother's suggestion, he submitted his des ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Psychedelic Music
Psychedelic music (sometimes called psychedelia) is a wide range of popular music styles and genres influenced by 1960s psychedelia, a subculture of people who used psychedelic drugs such as LSD, psilocybin mushrooms, mescaline, and cannabis to experience synesthesia and altered states of consciousness. Psychedelic music may also aim to enhance the experience of using these drugs and has been found to have a significant influence on psychedelic therapy. Psychedelia embraces visual art, movies, and literature, as well as music. Psychedelic music emerged during the 1960s among folk and rock bands in the United States and the United Kingdom, creating the subgenres of psychedelic folk, psychedelic rock, acid rock, and psychedelic pop before declining in the early 1970s. Numerous spiritual successors followed in the ensuing decades, including progressive rock, krautrock, and heavy metal. Since the 1970s, revivals have included psychedelic funk, neo-psychedelia, and stoner rock as ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Rock Music
Rock music is a broad genre of popular music that originated as " rock and roll" in the United States in the late 1940s and early 1950s, developing into a range of different styles in the mid-1960s and later, particularly in the United States and United Kingdom.W. E. Studwell and D. F. Lonergan, ''The Classic Rock and Roll Reader: Rock Music from its Beginnings to the mid-1970s'' (Abingdon: Routledge, 1999), p.xi It has its roots in 1940s and 1950s rock and roll, a style that drew directly from the blues and rhythm and blues genres of African-American music and from country music. Rock also drew strongly from a number of other genres such as electric blues and folk, and incorporated influences from jazz, classical, and other musical styles. For instrumentation, rock has centered on the electric guitar, usually as part of a rock group with electric bass guitar, drums, and one or more singers. Usually, rock is song-based music with a time signature using a verse–chorus form, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |