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Pitch Circularity
Pitch circularity is a fixed series of tones that are perceived to ascend or descend endlessly in pitch. It's an example of an auditory illusion. Explanation Pitch is often defined as extending along a one-dimensional continuum from high to low, as can be experienced by sweeping one’s hand up or down a piano keyboard. This continuum is known as pitch height. However pitch also varies in a circular fashion, known as pitch class: as one plays up a keyboard in semitone steps, C, C, D, D, E, F, F, G, G, A, A and B sound in succession, followed by C again, but one octave higher. Because the octave is the most consonant interval after the unison, tones that stand in octave relation, and are so of the same pitch class, have a certain perceptual equivalence—all Cs sound more alike to other Cs than to any other pitch class, as do all Ds, and so on; this creates the auditory equivalent of a Barber's pole, where all tones of the same pitch class are located on the same side of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impossible Staircase
The Penrose stairs or Penrose steps, also dubbed the impossible staircase, is an impossible object created by Oscar Reutersvärd in 1937 and later independently discovered and made popular by Lionel Penrose and his son Roger Penrose. A variation on the Penrose triangle, it is a two-dimensional depiction of a staircase in which the stairs make four 90-degree turns as they ascend or descend yet form a continuous loop, so that a person could climb them forever and never get any higher. This is clearly impossible in three-dimensional Euclidean geometry but possible in some non-Euclidean geometry like in nil geometry. The "continuous staircase" was first presented in an article that the Penroses wrote in 1959, based on the so-called "triangle of Penrose" published by Roger Penrose in the ''British Journal of Psychology'' in 1958. M.C. Escher then discovered the Penrose stairs in the following year and made his now famous lithograph ''Klimmen en dalen'' (''Ascending and Descending'') in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musical Note
In music, a note is the representation of a musical sound. Notes can represent the pitch and duration of a sound in musical notation. A note can also represent a pitch class. Notes are the building blocks of much written music: discretizations of musical phenomena that facilitate performance, comprehension, and analysis. The term ''note'' can be used in both generic and specific senses: one might say either "the piece ' Happy Birthday to You' begins with two notes having the same pitch", or "the piece begins with two repetitions of the same note". In the former case, one uses ''note'' to refer to a specific musical event; in the latter, one uses the term to refer to a class of events sharing the same pitch. (See also: Key signature names and translations.) Two notes with fundamental frequencies in a ratio equal to any integer power of two (e.g., half, twice, or four times) are perceived as very similar. Because of that, all notes with these kinds of relations can be grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitch (music)
Pitch is a perceptual property of sounds that allows their ordering on a frequency-related scale, or more commonly, pitch is the quality that makes it possible to judge sounds as "higher" and "lower" in the sense associated with musical melodies. Pitch is a major auditory attribute of musical tones, along with duration, loudness, and timbre. Pitch may be quantified as a frequency, but pitch is not a purely objective physical property; it is a subjective psychoacoustical attribute of sound. Historically, the study of pitch and pitch perception has been a central problem in psychoacoustics, and has been instrumental in forming and testing theories of sound representation, processing, and perception in the auditory system. Perception Pitch and frequency Pitch is an auditory sensation in which a listener assigns musical tones to relative positions on a musical scale based primarily on their perception of the frequency of vibration. Pitch is closely related to frequency, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Illusion
Auditory illusions are false perceptions of a real sound or outside stimulus. These false perceptions are the equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or sounds that should not be possible given the circumstance on how they were created. Humans are fairly susceptible to illusions, despite an innate ability to process complex stimuli. Confirmation bias is believed to be largely responsible for the inaccurate judgments that people make when evaluating information, given that humans typically interpret and recall information that appeals to their own biases. Amongst these misinterpretations, known as illusions, falls the category of auditory illusions. The brain uses multiple senses simultaneously to process information, spatial information is processed with greater detail and accuracy in vision than in hearing. Auditory illusions highlight areas where the human ear and brain, as organic survival tools, differentiate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuum (theory)
Continuum theories or models explain variation as involving gradual quantitative transitions without abrupt changes or discontinuities. In contrast, categorical theories or models explain variation using qualitatively different states. In physics In physics, for example, the space-time continuum model describes space and time as part of the same continuum rather than as separate entities. A spectrum in physics, such as the electromagnetic spectrum, is often termed as either continuous (with energy at all wavelengths) or discrete (energy at only certain wavelengths). In contrast, quantum mechanics uses quanta, certain defined amounts (i.e. categorical amounts) which are distinguished from continuous amounts. In mathematics and philosophy A good introduction to the philosophical issues involved is John Lane Bell'essayin th''Stanford Encyclopedia of Philosophy'' A significant divide is provided by the law of excluded middle. It determines the divide between intuition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitch Class
In music, a pitch class (p.c. or pc) is a set of all pitches that are a whole number of octaves apart; for example, the pitch class C consists of the Cs in all octaves. "The pitch class C stands for all possible Cs, in whatever octave position." Important to musical set theory, a pitch class is "all pitches related to each other by octave, enharmonic equivalence, or both." Thus, using scientific pitch notation, the pitch class "C" is the set : = . Although there is no formal upper or lower limit to this sequence, only a few of these pitches are audible to humans. Pitch class is important because human pitch-perception is periodic: pitches belonging to the same pitch class are perceived as having a similar quality or color, a property called " octave equivalence". Psychologists refer to the quality of a pitch as its "chroma". A ''chroma'' is an attribute of pitches (as opposed to ''tone height''), just like hue is an attribute of color. A ''pitch class'' is a set of all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octave
In music, an octave ( la, octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music," the use of which is "common in most musical systems." The interval between the first and second harmonics of the harmonic series is an octave. In Western music notation, notes separated by an octave (or multiple octaves) have the same name and are of the same pitch class. To emphasize that it is one of the perfect intervals (including unison, perfect fourth, and perfect fifth), the octave is designated P8. Other interval qualities are also possible, though rare. The octave above or below an indicated note is sometimes abbreviated ''8a'' or ''8va'' ( it, all'ottava), ''8va bassa'' ( it, all'ottava bassa, sometimes also ''8vb''), or simply ''8'' for the octave in the direction indicated by pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unison
In music, unison is two or more musical parts that sound either the same pitch or pitches separated by intervals of one or more octaves, usually at the same time. ''Rhythmic unison'' is another term for homorhythm. Definition Unison or perfect unison (also called a prime, or perfect prime)Benward & Saker (2003), p. 53. may refer to the (pseudo-) interval formed by a tone and its duplication (in German, ''Unisono'', ''Einklang'', or ''Prime''), for example C–C, as differentiated from the second, C–D, etc. In the unison the two pitches have the ratio of 1:1 or 0 half steps and zero cents. Although two tones in unison are considered to be the same pitch, they are still perceivable as coming from separate sources, whether played on instruments of a different type: ; or of the same type: . This is because a pair of tones in unison come from different locations or can have different "colors" ( timbres), i.e. come from different musical instruments or human voices. Voices wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barber's Pole
A barber's pole is a type of sign used by barbers to signify the place or shop where they perform their craft. The trade sign is, by a tradition dating back to the Middle Ages, a staff or pole with a helix of colored stripes (often red and white in many countries, but usually red, white and blue in the United States). The pole may be stationary or may rotate, often with the aid of an electric motor. A "barber's pole" with a helical stripe is a familiar sight, and is used as a secondary metaphor to describe objects in many other contexts. For example, if the shaft or tower of a lighthouse has been painted with a helical stripe as a daymark, the lighthouse could be described as having been painted in "barber's pole" colors. Origin in barbering and surgery During medieval times, barbers performed surgery on customers, as well as tooth extractions. The original pole had a brass wash basin at the top (representing the vessel in which leeches were kept) and bottom (representing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roger Shepard
Roger Newland Shepard (January 30, 1929 – May 30, 2022) was an American cognitive scientist and author of the "universal law of generalization" (1987). He was considered a father of research on spatial relations. He studied mental rotation, and was an inventor of non-metric multidimensional scaling, a method for representing certain kinds of statistical data in a graphical form that can be apprehended by humans. The optical illusion called Shepard tables and the auditory illusion called Shepard tones are named for him. Biography Shepard was born January 30, 1929 in Palo Alto, California. His father was a professor of materials science at Stanford. As a child and teenager, he enjoyed tinkering with old clockworks, building robots, and making models of regular polyhedra. He attended Stanford as an undergraduate, eventually majoring in psychology and graduating in 1951. Shepard obtained his Ph.D. in psychology at Yale University in 1955 under Carl Hovland, and completed post- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roger N
Roger is a given name, usually masculine, and a surname. The given name is derived from the Old French personal names ' and '. These names are of Germanic origin, derived from the elements ', ''χrōþi'' ("fame", "renown", "honour") and ', ' ("spear", "lance") (Hrōþigēraz). The name was introduced into England by the Normans. In Normandy, the Frankish name had been reinforced by the Old Norse cognate '. The name introduced into England replaced the Old English cognate '. ''Roger'' became a very common given name during the Middle Ages. A variant form of the given name ''Roger'' that is closer to the name's origin is ''Rodger''. Slang and other uses Roger is also a short version of the term "Jolly Roger", which refers to a black flag with a white skull and crossbones, formerly used by sea pirates since as early as 1723. From up to , Roger was slang for the word "penis". In ''Under Milk Wood'', Dylan Thomas writes "jolly, rodgered" suggesting both the sexual double ente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Claude Risset
Jean-Claude Raoul Olivier Risset (; 13 March 1938 – 21 November 2016) was a French composer, best known for his pioneering contributions to computer music. He was a former student of André Jolivet and former co-worker of Max Mathews at Bell Labs. Biography Risset was born in Le Puy-en-Velay, France. Arriving at Bell Labs, New Jersey in 1964, he used Max Mathews' MUSIC IV software to digitally recreate the sounds of brass instruments. He made digital recordings of trumpets and studied their timbral composition using "pitch-synchronous" spectrum analysis tools, revealing that the amplitude and frequency of the harmonics (more correctly, partials) of these instruments would differ depending on frequency, duration and amplitude. He is also credited with performing the first experiments on a range of synthesis techniques including FM synthesis and waveshaping. After the discrete Shepard scale Risset created a version of the scale where the steps between each tone are continuo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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