Andrew

Andrew is the English form of a given name common in many countries. 　In the 1990s, it was among the top ten most popular names given to boys in English-speaking countries. 　"Andrew" is frequently shortened to "Andy" or "Drew". 　The word is derived from the Greek: Ἀνδρέας, Andreas, itself related to Ancient Greek: ἀνήρ/ἀνδρός aner/andros, "man" (as opposed to "woman"), thus meaning "manly" and, as consequence, "brave", "strong", "courageous", and "warrior". 　In the King James Bible, the Greek "Ἀνδρέας" is translated as Andrew.

Dry

Look up DRY, driest, dry, or dryness in Wiktionary, the free dictionary. 　Dry or dryness most often refers to: Lack of rainfall, which may refer to Arid regions Drought Dry or dry area, relating to legal prohibition of selling, serving, or imbibing alcoholic beverages Dry humor, deadpan Dryness (medical) Dryness (taste), the lack of sugar in a drink, especially an alcoholic one Dry direct sound without reverberation Dry or DRY may also refer to:

Engineer

Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. 　The word engineer (Latin ingeniator) is derived from the Latin words ingeniare ("to contrive, devise") and ingenium ("cleverness"). 　The foundational qualifications of an engineer typically include a four-year bachelor's degree in an engineering discipline, or in some jurisdictions, a master's degree in an engineering discipline plus four to six years of peer-reviewed professional practice (culminating in a project report or thesis) and passage of engineering board examinations. 　The work of engineers forms the link between scientific discoveries and their subsequent applications to human and business needs and quality of life.

Stock (geology)

In geology, a stock is an igneous intrusion that has a surface exposure of less than 100 square kilometres (40 sq mi), differing from batholiths only in being smaller. 　A stock has a discordant relationship with the rocks that it intrudes. 　Many stocks are cupolas of hidden batholiths. 　Some circular or elliptical stocks may be volcanic plugs, which fill the vents of now extinct volcanoes. 　A boss is a small stock.

Stock

In finance, stock (also capital stock) consists of all the shares by which ownership of a corporation or company is divided. 　(Especially in American English, the word "stocks" is also used to refer to shares.) 　A single share of the stock means fractional ownership of the corporation in proportion to the total number of shares. 　This typically entitles the shareholder (stockholder) to that fraction of the company's earnings, proceeds from liquidation of assets (after discharge of all senior claims such as secured and unsecured debt), or voting power, often dividing these up in proportion to the amount of money each stockholder has invested. 　Not all stock is necessarily equal, as certain classes of stock may be issued for example without voting rights, with enhanced voting rights, or with a certain priority to receive profits or liquidation proceeds before or after other classes of shareholders. 　Stock can be bought and sold privately or on stock exchanges, and such transactions are typically heavily regulated by governments to prevent fraud, protect investors, and benefit the larger economy. 　The stocks are deposited with the depositories in the electronic format also known as Demat account. 　As new shares are issued by a company, the ownership and rights of existing shareholders are diluted in return for cash to sustain or grow the business. 　Companies can also buy back stock, which often lets investors recoup the initial investment plus capital gains from subsequent rises in stock price. 　Stock options issued by many companies as part of employee compensation do not represent ownership, but represent the right to buy ownership at a future time at a specified price. 　This would represent a windfall to the employees if the option is exercised when the market price is higher than the promised price, since if they immediately sold the stock they would keep the difference (minus taxes).

Combat

Combat (French for fight) is a purposeful violent conflict meant to physically harm or kill the opposition. 　Combat may be armed (using weapons) or unarmed (not using weapons). 　Combat is sometimes resorted to as a method of self-defense, or can be used as a tool to impose one's will on others. 　An instance of combat can be a stand-alone confrontation or a small part of a much larger violent conflict. 　Instances of combat may also be benign and recreational, as in the cases of combat sports and mock combat. 　Combat may comply with, or be in violation of local or international laws regarding conflict. 　Examples of rules include the Geneva Conventions (covering the treatment of people in war), medieval chivalry, the Marquess of Queensberry rules (covering boxing) and several forms of combat sports.

Unless

Unless is the final novel by Canadian writer Carol Shields, first published by Fourth Estate, an imprint of HarperCollins in 2002. 　Semi-autobiographical, it was the capstone to Shields's writing career: she died shortly after its publication in 2003. 　The work was widely acclaimed and nominated for the Booker Prize, the Giller Prize, the Governor General's Award, the Orange Prize for Fiction, and received the Ethel Wilson Fiction Prize. 　In 2011, it was a finalist in the Canada Reads competition, where it was defended by actor Lorne Cardinal. 　Like many of her works (especially The Stone Diaries), Unless explores the extraordinary that lies within the ordinary lives of ordinary women. 　The novel is narrated in first person by 44-year-old writer and translator, Reta Winters. 　The book proceeds as a linear series of reflections by Reta, elliptically coming to the thematic center of the story: the seemingly arbitrary decision of Reta's college-aged daughter Norah to drop out of university and live on the street with a cardboard sign affixed to her chest that reads "Goodness". 　Although the novel does not in any way proceed like a mystery, the reasons for Norah's departure from the normal world are Reta's primary motivation in writing. 　In parallel, her relationship with her French mentor (a Holocaust survivor and poet) drives much of her narration and view of herself. 　The novel deals extensively with the role of women and in particular, women's literature. 　Late in the novel, Reta starts to break from herself and write in character as a disenfranchised female writer. 　The underlying theme is that the lives of women are underwritten, ignored, and dealt with as "trivial" by the literary establishment. 　The novel also functions largely as an investigation into the role of writing in general (independent of gender). 　Reta's grief over her daughter's state makes her very inwardly focussed on the process of writing. 　A reflection of this is shown in the title of the book and the chapter titles. 　"Unless" and the chapter titles ("therefore", "else", "instead") are all words that are used to couch the fragmented manner in which life fits together. 　As Shields writes, "A life is full of isolated events, but these events, if they are to form a coherent narrative, require odd pieces of language to link them together, little chips of grammar (mostly adverbs or prepositions) that are hard to define [...] words like therefore, else, other, also, thereof, therefore, instead, otherwise, despite, already, and not yet." 　The novel was adapted into the 2016 film Unless, which stars Catherine Keener as Reta and Hannah Gross as Norah. 　On November 5, 2019, the BBC News listed Unless on its list of the 100 most influential novels.

Evil

Evil, in a general sense, is defined as the opposite or absence of good. 　It can be an extremely broad concept, although in everyday usage it is often more narrowly used to talk about profound wickedness and against common good. 　It is generally seen as taking multiple possible forms, such as the form of personal moral evil commonly associated with the word, or impersonal natural evil (as in the case of natural disasters or illnesses), and in religious thought, the form of the demonic or supernatural/eternal. 　While some religions, world views, and philosophies focus on "good versus evil", others deny evil's existence and usefulness in describing people. 　Evil can denote profound immorality, but typically not without some basis in the understanding of the human condition, where strife and suffering (cf. Hinduism) are the true roots of evil. 　In certain religious contexts, evil has been described as a supernatural force. 　Definitions of evil vary, as does the analysis of its motives. 　Elements that are commonly associated with personal forms of evil involve unbalanced behavior including anger, revenge, hatred, psychological trauma, expediency, selfishness, ignorance, destruction and neglect. 　In some forms of thought, evil is also sometimes perceived as the dualistic antagonistic binary opposite to good, in which good should prevail and evil should be defeated. 　In cultures with Buddhist spiritual influence, both good and evil are perceived as part of an antagonistic duality that itself must be overcome through achieving Nirvana. 　The ethical questions regarding good and evil are subsumed into three major areas of study: meta-ethics concerning the nature of good and evil, normative ethics concerning how we ought to behave, and applied ethics concerning particular moral issues. 　While the term is applied to events and conditions without agency, the forms of evil addressed in this article presume one or more evildoers.

Message

A message is a discrete unit of communication intended by the source for consumption by some recipient or group of recipients. 　A message may be delivered by various means, including courier, telegraphy, carrier pigeon and electronic bus. 　A message can be the content of a broadcast. 　An interactive exchange of messages forms a conversation. 　One example of a message is a press release, which may vary from a brief report or statement released by a public agency to commercial publicity material.

Bear

Bears are carnivoran mammals of the family Ursidae. 　They are classified as caniforms, or doglike carnivorans. 　Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the Northern Hemisphere and partially in the Southern Hemisphere. 　Bears are found on the continents of North America, South America, Europe, and Asia. 　Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. 　While the polar bear is mostly carnivorous, and the giant panda feeds almost entirely on bamboo, the remaining six species are omnivorous with varied diets. 　With the exception of courting individuals and mothers with their young, bears are typically solitary animals. 　They may be diurnal or nocturnal and have an excellent sense of smell. 　Despite their heavy build and awkward gait, they are adept runners, climbers, and swimmers. 　Bears use shelters, such as caves and logs, as their dens; most species occupy their dens during the winter for a long period of hibernation, up to 100 days. 　Bears have been hunted since prehistoric times for their meat and fur; they have been used for bear-baiting and other forms of entertainment, such as being made to dance. 　With their powerful physical presence, they play a prominent role in the arts, mythology, and other cultural aspects of various human societies. 　In modern times, bears have come under pressure through encroachment on their habitats and illegal trade in bear parts, including the Asian bile bear market. 　The IUCN lists six bear species as vulnerable or endangered, and even least concern species, such as the brown bear, are at risk of extirpation in certain countries. 　The poaching and international trade of these most threatened populations are prohibited, but still ongoing.

Battalion

A battalion is a military unit, typically consisting of 300 to 1,200 soldiers commanded by a lieutenant colonel, and subdivided into a number of companies (usually each commanded by a major or a captain). 　In some countries, battalions are exclusively infantry, while in others battalions are unit-level organizations. 　The word battalion came into the English language in the 16th century from the French language (French: bataillon meaning "battle squadron"; Italian: battaglione meaning the same thing; derived from the Vulgar Latin word battalia meaning "battle" and from the Latin word bauttere meaning "to beat" or "to strike"). 　The first use of the word in English was in the 1580s.

Violence

Violence is "the use of physical force so as to injure, abuse, damage, or destroy". 　Other definitions are also used, such as the World Health Organization's definition of violence as "the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, which either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment, or deprivation." 　Internationally, violence resulted in deaths of an estimated 1.28 million people in 2013 up from 1.13 million in 1990. 　However, global population grew by roughly 1.9 billion during those years, showing a dramatic reduction in violence per capita. 　Of the deaths in 2013, roughly 842,000 were attributed to self-harm (suicide), 405,000 to interpersonal violence, and 31,000 to collective violence (war) and legal intervention. 　For each single death due to violence, there are dozens of hospitalizations, hundreds of emergency department visits, and thousands of doctors' appointments. 　Furthermore, violence often has lifelong consequences for physical and mental health and social functioning and can slow economic and social development. 　In 2013, of the estimated 405,000 deaths due to interpersonal violence globally, assault by firearm was the cause in 180,000 deaths, assault by sharp object was the cause in 114,000 deaths, and the remaining 110,000 deaths from other causes. 　Violence in many forms can be preventable. 　There is a strong relationship between levels of violence and modifiable factors in a country such as an concentrated (regional) poverty, income and gender inequality, the harmful use of alcohol, and the absence of safe, stable, and nurturing relationships between children and parents. 　Strategies addressing the underlying causes of violence can be relatively effective in preventing violence, although mental and physical health and individual responses, personalities, etc. have always been decisive factors in the formation of these behaviors.

Leg

A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. 　During locomotion, legs function as "extensible struts". 　The combination of movements at all joints can be modeled as a single, linear element capable of changing length and rotating about an omnidirectional "hip" joint. 　As an anatomical animal structure it is used for locomotion. 　The distal end is often modified to distribute force (such as a foot). 　Most animals have an even number of legs. 　As a component of furniture, it is used for the economy of materials needed to provide the support for the useful surface, such as the table top or chair seat.

Circle

A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. 　Equivalently, it is the curve traced out by a point that moves in a plane so that its distance from a given point is constant. 　The distance between any point of the circle and the centre is called the radius. 　Usually, the radius is required to be a positive number. 　A circle with r = 0 {\displaystyle r=0} (a single point) is a degenerate case. 　This article is about circles in Euclidean geometry, and, in particular, the Euclidean plane, except where otherwise noted. 　Specifically, a circle is a simple closed curve that divides the plane into two regions: an interior and an exterior. 　In everyday use, the term "circle" may be used interchangeably to refer to either the boundary of the figure, or to the whole figure including its interior; in strict technical usage, the circle is only the boundary and the whole figure is called a disc. 　A circle may also be defined as a special kind of ellipse in which the two foci are coincident, the eccentricity is 0, and the semi-major and semi-minor axes are equal; or the two-dimensional shape enclosing the most area per unit perimeter squared, using calculus of variations.

Reality

Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only imaginary, nonexistent or nonactual. 　The term is also used to refer to the ontological status of things, indicating their existence. 　In physical terms, reality is the totality of a system, known and unknown. 　Philosophical questions about the nature of reality or existence or being are considered under the rubric of ontology, which is a major branch of metaphysics in the Western philosophical tradition. 　Ontological questions also feature in diverse branches of philosophy, including the philosophy of science, of religion, of mathematics, and philosophical logic. 　These include questions about whether only physical objects are real (i.e., physicalism), whether reality is fundamentally immaterial (e.g. idealism), whether hypothetical unobservable entities posited by scientific theories exist, whether a 'God' exists, whether numbers and other abstract objects exist, and whether possible worlds exist. 　Epistemology is concerned with what can be known or inferred as likely and how, whereby in the modern world emphasis is put on reason, empirical evidence and science as sources and methods to determine or investigate reality.

Coffee

Coffee is a drink prepared from roasted coffee beans. 　Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. 　It has the highest sales in the world market for hot drinks. 　Seeds of the Coffea plant's fruits are separated to produce unroasted green coffee beans. 　The beans are roasted and then ground into fine particles that are typically steeped in hot water before being filtered out, producing a cup of coffee. 　It is usually served hot, although chilled or iced coffee is common. 　Coffee can be prepared and presented in a variety of ways (e.g., espresso, French press, caffè latte, or already-brewed canned coffee). 　Sugar, sugar substitutes, milk, and cream are often used to mask the bitter taste or enhance the flavor. 　Though coffee is now a global commodity, it has a long history tied closely to food traditions around the Red Sea. 　The earliest credible evidence of coffee drinking in the form of the modern beverage appears in modern-day Yemen from the mid-15th century in Sufi shrines, where coffee seeds were first roasted and brewed in a manner similar to current methods. 　The Yemenis procured the coffee beans from the Ethiopian Highlands via coastal Somali intermediaries and began cultivation. 　By the 16th century, the drink had reached the rest of the Middle East and North Africa, later spreading to Europe. 　In the 20th century, coffee became a global commodity, creating different coffee cultures around the world. 　The two most commonly grown coffee bean types are C. arabica and C. robusta. 　Coffee plants are cultivated in over 70 countries, primarily in the equatorial regions of the Americas, Southeast Asia, the Indian subcontinent, and Africa. 　As of 2018[update], Brazil was the leading grower of coffee beans, producing 35% of the world's total. 　Green, unroasted coffee is traded as an agricultural commodity. 　Despite sales of coffee reaching billions of dollars worldwide, farmers producing coffee beans disproportionately live in poverty. 　Critics of the coffee industry have also pointed to its negative impact on the environment and the clearing of land for coffee-growing and water use.

Particle (ecology)

In marine and freshwater ecology, a particle is a small object. 　Particles can remain in suspension in the ocean or freshwater. 　However, they eventually settle (rate determined by Stokes' law) and accumulate as sediment. 　Some can enter the atmosphere through wave action where they can act as cloud condensation nuclei (CCN). 　Many organisms filter particles out of the water with unique filtration mechanisms (filter feeders). 　Particles are often associated with high loads of toxins which attach to the surface. 　As these toxins are passed up the food chain they accumulate in fatty tissue and become increasingly concentrated in predators (see bioaccumulation). 　Very little is known about the dynamics of particles, especially when they are re-suspended by dredging. 　They can remain floating in the water and drift over long distances. 　The decomposition of some particles by bacteria consumes much oxygen and can cause the water to become hypoxic.

Particle

In the physical sciences, a particle (or corpuscule in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. 　They vary greatly in size or quantity, from subatomic particles like the electron, to microscopic particles like atoms and molecules, to macroscopic particles like powders and other granular materials. 　Particles can also be used to create scientific models of even larger objects depending on their density, such as humans moving in a crowd or celestial bodies in motion. 　The term particle is rather general in meaning, and is refined as needed by various scientific fields. 　Anything that is composed of particles may be referred to as being particulate. 　However, the noun particulate is most frequently used to refer to pollutants in the Earth's atmosphere, which are a suspension of unconnected particles, rather than a connected particle aggregation.

Audience

An audience is a group of people who participate in a show or encounter a work of art, literature (in which they are called "readers"), theatre, music (in which they are called "listeners"), video games (in which they are called "players"), or academics in any medium. 　Audience members participate in different ways in different kinds of art. 　Some events invite overt audience participation and others allow only modest clapping and criticism and reception. 　Media audience studies have become a recognized part of the curriculum. 　Audience theory offers scholarly insight into audiences in general. 　These insights shape our knowledge of just how audiences affect and are affected by different forms of art. 　The biggest art form is the mass media. 　Films, video games, radio shows, software (and hardware), and other formats are affected by the audience and its reviews and recommendations. 　In the age of easy internet participation and citizen journalism, professional creators share space, and sometimes attention with the public. 　American journalist Jeff Jarvis said, "Give the people control of media, they will use it. The corollary: Don't give the people control of media, and you will lose. Whenever citizens can exercise control, they will." 　Tom Curley, President of the Associated Press, similarly said, "The users are deciding what the point of their engagement will be — what application, what device, what time, what place."

Desire

Desires are states of mind that are expressed by terms like "wanting", "wishing", "longing" or "craving". 　A great variety of features is commonly associated with desires. 　They are seen as propositional attitudes towards conceivable states of affairs. 　They aim to change the world by representing how the world should be, unlike beliefs, which aim to represent how the world actually is. 　Desires are closely related to agency: they motivate the agent to realize them. 　For this to be possible, a desire has to be combined with a belief about which action would realize it. 　Desires present their objects in a favorable light, as something that appears to be good. 　Their fulfillment is normally experienced as pleasurable in contrast to the negative experience of failing to do so. 　Conscious desires are usually accompanied by some form of emotional response. 　While many researchers roughly agree on these general features, there is significant disagreement about how to define desires, i.e. which of these features are essential and which ones are merely accidental. 　Action-based theories define desires as structures that incline us toward actions. 　Pleasure-based theories focus on the tendency of desires to cause pleasure when fulfilled. 　Value-based theories identify desires with attitudes toward values, like judging or having an appearance that something is good. 　Desires can be grouped into various types according to a few basic distinctions. 　Intrinsic desires concern what the subject wants for its own sake while instrumental desires are about what the subject wants for the sake of something else. 　Occurrent desires are either conscious or otherwise causally active, in contrast to standing desires, which exist somewhere in the back of one's mind. 　Propositional desires are directed at possible states of affairs while object-desires are directly about objects. 　Various authors distinguish between higher desires associated with spiritual or religious goals and lower desires, which are concerned with bodily or sensory pleasures. 　Desires play a role in many different fields. 　There is disagreement whether desires should be understood as practical reasons or whether we can have practical reasons without having a desire to follow them. 　According to fitting-attitude theories of value, an object is valuable if it is fitting to desire this object or if we ought to desire it. 　Desire-satisfaction theories of well-being state that a person's well-being is determined by whether that person's desires are satisfied. 　Marketing and advertising companies have used psychological research on how desire is stimulated to find more effective ways to induce consumers into buying a given product or service. 　Techniques include creating a sense of lack in the viewer or associating the product with desirable attributes. 　Desire plays a key role in art. 　The theme of desire is at the core of romance novels, which often create drama by showing cases where human desire is impeded by social conventions, class, or cultural barriers. 　Melodrama films use plots that appeal to the heightened emotions of the audience by showing "crises of human emotion, failed romance or friendship", in which desire is thwarted or unrequited.

Crowd

Generally speaking, a crowd is defined as a group of people that have gathered for a common purpose or intent such as at a demonstration, a sports event, or during looting (this is known as an acting crowd), or may simply be made up of many people going about their business in a busy area. 　The term "the crowd" may sometimes refer to the lower orders of people in general.

Exhibition

An exhibition, in the most general sense, is an organized presentation and display of a selection of items. 　In practice, exhibitions usually occur within a cultural or educational setting such as a museum, art gallery, park, library, exhibition hall, or World's fairs. 　Exhibitions can include many things such as art in both major museums and smaller galleries, interpretive exhibitions, natural history museums and history museums, and also varieties such as more commercially focused exhibitions and trade fairs. 　In British English the word "exhibition" is used for a collection of items placed on display and the event as a whole, which in American English is usually an "exhibit". 　In both varieties of English each object being shown within an exhibition is an "exhibit". 　In common usage, "exhibitions" are considered temporary and usually scheduled to open and close on specific dates. 　While many exhibitions are shown in just one venue, some exhibitions are shown in multiple locations and are called travelling exhibitions, and some are online exhibitions. 　Exhibitions featuring especially fragile or valuable objects, or live animals—may be shown only during a formal presentation, under the close supervision of attendant or educator. 　Temporary exhibits that are transported from institution to institution are traveling exhibits. 　Though exhibitions are common events, the concept of an exhibition is quite wide and encompasses many variables. 　Exhibitions range from an extraordinarily large event such as a World's fair exposition to small one-artist solo shows or a display of just one item. 　Often a team of specialists is required to assemble and execute an exhibition; these specialists vary depending on the type of said exhibit. 　Curators are sometimes involved as the people who select the items in an exhibition. 　Writers and editors are sometimes needed to write text, labels and accompanying printed material such as catalogs and books. 　Architects, exhibition designers, graphic designers and other designers may be needed to shape the exhibition space and give form to the editorial content. 　Organizing and holding exhibitions also requires effective event planning, management, and logistics.

Orchestra

An orchestra (/ˈɔːrkɪstrə/; Italian: [orˈkɛstra]) is a large instrumental ensemble typical of classical music, which combines instruments from different families. 　There are typically four main sections of instruments: bowed string instruments, such as the violin, viola, cello, and double bass woodwinds, such as the flute, oboe, clarinet, saxophone, and bassoon Brass instruments, such as the horn, trumpet, trombone, cornet, and tuba percussion instruments, such as the timpani, snare drum, bass drum, cymbals, triangle, tambourine, and mallet percussion instruments Other instruments such as the piano, harpsichord, and celesta may sometimes appear in a fifth keyboard section or may stand alone as soloist instruments, as may the concert harp and, for performances of some modern compositions, electronic instruments and guitars. 　A full-size Western orchestra may sometimes be called a symphony orchestra or philharmonic orchestra (from Greek phil-, "loving", and "harmony"). 　The actual number of musicians employed in a given performance may vary from seventy to over one hundred musicians, depending on the work being played and the size of the venue. 　A chamber orchestra (sometimes concert orchestra) is a smaller ensemble of not more than about fifty musicians. 　Orchestras that specialize in the Baroque music of, for example, Johann Sebastian Bach and George Frideric Handel, or Classical repertoire, such as that of Haydn and Mozart, tend to be smaller than orchestras performing a Romantic music repertoire such as the symphonies of Ludwig van Beethoven and Johannes Brahms. 　The typical orchestra grew in size throughout the 18th and 19th centuries, reaching a peak with the large orchestras (of as many as 120 players) called for in the works of Richard Wagner, and later, Gustav Mahler. 　Orchestras are usually led by a conductor who directs the performance with movements of the hands and arms, often made easier for the musicians to see by use of a conductor's baton. 　The conductor unifies the orchestra, sets the tempo and shapes the sound of the ensemble. 　The conductor also prepares the orchestra by leading rehearsals before the public concert, in which the conductor provides instructions to the musicians on their interpretation of the music being performed. 　The leader of the first violin section – commonly called the concertmaster – also plays an important role in leading the musicians. 　In the Baroque music era (1600–1750), orchestras were often led by the concertmaster, or by a chord-playing musician performing the basso continuo parts on a harpsichord or pipe organ, a tradition that some 20th century and 21st century early music ensembles continue. 　Orchestras play a wide range of repertoire, including symphonies, opera and ballet overtures, concertos for solo instruments, and as pit ensembles for operas, ballets, and some types of musical theatre (e.g., Gilbert and Sullivan operettas). 　Amateur orchestras include those made up of students from an elementary school or a high school, youth orchestras, and community orchestras; the latter two typically being made up of amateur musicians from a particular city or region. 　The term orchestra derives from the Greek ὀρχήστρα (orchestra), the name for the area in front of a stage in ancient Greek theatre reserved for the Greek chorus.

Bell

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.