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Welcome! We are an encyclopedia project, and more. We are a different sort of Web 2.0 project: We aim at credibility and quality, not just quantity. Both the general public and credentialed experts are encouraged to get involved. We use our real names, not pseudonyms. We're collegial. We have added over 3,200 articles (and many subpages) since November 2006. Join us! New authors and editors welcome! A human being will respond usually within a few hours. Learn about us For readers: About the Citizendium For authors: The Author Role For editors: The Editor Role Initiatives Core Articles - tackle high priority topics Recruitment - help invite others to join Subpages - add other types of info to CZ What's Your Article? - a place to display your best Support us We're a 501(c)(3) non-profit, and we need your support. If you shop at Amazon or Barnes & Noble and you access these sites by the links provided here, we'll be getting donations at no cost to you (read more) - Search All Products.	Some of our finest [ about ] Approved Articles Developed Articles (over 600) Draft of the Week [ about ] Tennis is a sport played between either two players ("singles") or two teams of two players ("doubles"). Players use a stringed racquet to strike a hollow rubber ball covered with felt over a net into the opponent's court. In some places tennis is still called lawn tennis to distinguish it from real tennis (also known as royal tennis or court tennis), an older form of the game that originated in France in the Middle Ages and is played indoors on a very different court. Originating in England in the late 19th century, lawn tennis first spread throughout the English-speaking world, particularly among the upper classes. Today tennis is an Olympic sport that is played at all levels of society, by all ages, and in many countries around the world. Except for the adoption of the tie-breaker in the 1970s, its rules have remained remarkably unchanged since the 1890s. Millions of people also follow tennis as a spectator sport, especially the four Grand Slam tournaments. [more...] New Draft of the Week [ about ] A symphony is a large-scale musical composition for an orchestra. Since the late eighteenth century, composers have regarded the symphony as “the central form of orchestral composition”, similar to how writers of fiction regard the novel, and filmmakers the feature film. According to music historian Michael Kennedy, the symphony “is reserved by composers for their most weighty and profound orchestral thoughts, but of course there are many light-hearted, witty, and entertaining symphonies.” In the present day the symphony is the musical form performed more than any other in concert programs by orchestras in the United States and Europe. [more...]