Opus, from the Latin word opus meaning "work", is usually used in the sense of "a work of art". In this sense the plural of opus, "opera", is used to refer to the genre of music drama. Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... In fine art, a work of art (or artwork or work) is a creation, such as a song, book, sculpture or a painting, that has been made in order to be a thing of beauty in itself or a symbolic statement of meaning, rather than having a practical function. ...

Since about the 17th century, many composers have identified their musical works by opus numbers. This is abbreviated "Op."; the plural is "Opp." Through about 1800, these were normally assigned by publishers who published groups of like works together, usually in sets of 3, 6, or 12. They consequently often have little relationship to chronological order of composition, even when this may be determined. Those works that did not happen to get published at the time lack opus numbers. Also, gaps and duplications in the numbering sequences, especially when multiple publishers are involved, are frequent. Some examples of this are discussed below under individual composers. Many opus numbers, such as those of Mozart, are so useless and so adequately replaced by catalogs that they are no longer used to identify the works at all. The multiple-set opus numbers best-known today are those of the string quartets of Joseph Haydn. Haydn's Op. 76, for instance, consists of six quartets, known individually as Op. 76 No. 1, etc., while his Op. 74 consists of three quartets, similarly identified. A composer is a person who writes music. ... Allegory of Music on the Opéra Garnier Music is an art form that involves organized sounds and silence. ... Mozart redirects here. ... The resident string quartet of the Library of Congress in 1963 A string quartet is a musical ensemble of four string instruments—usually two violins, a viola and cello—or a piece written to be performed by such a group. ... This article or section does not cite its references or sources. ...

Starting about 1800, especially with the works of Beethoven, opus numbers tended to be assigned by the composer and were more usually applied to individual works (though later composers often continued to assign opus numbers to sets, especially of short piano pieces and songs). Gradually the connection between opus number and publication has been lost, and many composers since 1900 have given opus numbers to works that are not necessarily published at all. Consequently opus numbers, when present, are a better guide to chronology of composition, though they are not always reliable. Beethoven was very selective in his early years about which works he assigned opus numbers to, omitting numbers even on some works he sent for publication. (Many in this category have since his death been assigned numbers labeled "WoO", standing for "Werk ohne Opuszahl" or "work without an opus number.") However, in later years he published some very early works with higher opus numbers, and some works published posthumously were also given opus numbers. 1820 portrait by Joseph Karl Stieler Beethoven redirects here. ... The word Woo may have a number of meanings: Courtship. ...

The practice of posthumous opus numbers, sometimes but not always labeled "Op. posth.", is most striking in the case of Felix Mendelssohn. Subsequent to his death, many works were published by his heirs with opus numbers. For example, Mendelssohn published in his lifetime three symphonies, numbers 1-3, with the opus numbers 11, 52, and 56. Two symphonies composed between No. 1 and No. 2, but withdrawn by the composer, the "Italian" and the "Reformation", were published after his death and called No. 4 and No. 5 respectively, with the opus numbers 90 and 107. Felix Mendelssohn at the age of 30 Jakob Ludwig Felix Mendelssohn Bartholdy, born and known generally as Felix Mendelssohn (February 3, 1809 – November 4, 1847) was a German composer and conductor of the early Romantic period. ...

Some composers, such as Cesar Franck and Bela Bartok, used opus numbers early in their careers but soon dropped them; others, such as Carl Nielsen and Paul Hindemith, were inconsistent about using them. Others, however, have been strict and conscientious, most notably Serge Prokofiev, who habitually assigned opus numbers to works before beginning to compose them, thus leaving some fragmentary or planned works with opus numbers on his death, and even assigning new opus numbers to revised works; thus his Symphony No. 4 is both Op. 47 and Op. 112, and his Piano Sonata No. 5 is both Op. 38 and Op. 135, depending on the edition. C sar-Auguste-Jean-Guillaume-Hubert Franck (December 10, 1822–November 8, 1890) was a composer and organist. ... B la Bart k (March 25, 1881 – September 26, 1945) was a composer, pianist and collector of East European folk music. ... Carl Nielsen Carl August Nielsen (June 9, 1865, Sortelung – October 3, 1931, Copenhagen) was a conductor, violinist, and the most internationally known composer from Denmark. ... Paul Hindemith (16 November 1895 – 28 December 1963) was a German composer, violist, violinist, teacher, music theorist and conductor. ... Sergei Sergeyevich Prokofiev (Серге́й Серге́евич Проко́фьев) (April 271, 1891 – March 5, 1953) was one of the Soviet Unions greatest composers. ...

Because of the problems of using opus numbers to identify works particularly for composers from the baroque and classical eras, and the absence and scattered use of opus numbers by composers of all eras, many composers' works have been definitely cataloged by individual scholars, and in such cases their works may be unambiguously referred to by their thematic catalog abbreviations. The Classical period in Western music occurred from about 1730 through 1820, despite considerable overlap at both ends with preceding and following periods, as is true for all musical eras. ...

• The works of Karl Friedrich Abel, while usually referenced by their original publication opus numbers (for example, his Op. 17 symphonies), also have catalog numbers assigned to them by Walter Knape in his Bibliographisch-thematisches Verzeichnis der Kompositionen von Karl Friedrich Abel (Cuxhaven: W. Knape, 1972).
• Carl Philipp Emanuel Bach's works have two numbering systems: the older Wotquenne numbering (abbreviated as Wq.) devised by Alfred Wotquenne in his catalog of Emanuel's music published in 1905, and the more complete and up-to-date numbering by E. Eugene Helm (abbreviated as H.), as presented in Helm's Thematic Catalogue of the Works of C.P.E. Bach (New Haven: Yale University Press, 1989).
• Johann Christian Bach's works are most often referred to by the opus numbers assigned by their original publishers, which can cause identification difficulties because different publishers used the same opus number. (For instance, "Op. 18" was used for three different sets of J.C. Bach works: "Six Grand Overtures," "Deux sinfonies," and "Four Sonatas and Two Duets," and three of his six Op. 6 symphonies also appear in his Op. 8 in a different order.) Because of this, some have used C.S. Terry's John Christian Bach (2nd edition; London: Oxford University Press, 1967) as the basis for a de facto standard, using the page number and incipit number in Terry for identification even though these numbers were not assigned by Terry for cataloguing purposes. (For a convenient short listing of these numbers, see Christoph Wolff, et al., The New Grove Bach Family [NY: Norton, 1983], pp. 341ff..) Numbers are also sometimes used from the Thematic Catalog in the Collected Works of Johann Christian Bach (gen. ed. Ernest Warburton; NY: Garland Publishing, 1985).
• Johann Sebastian Bach's works are referred to by their BWV or Bach-Werke-Verzeichnis numbers after the catalogue by Wolfgang Schmieder.
• Wilhelm Friedemann Bach's works were catalogued by Martin Falck in 1913, and are often referred to by their F (or Falck) numbers.
• Dietrich Buxtehude's works are referred to by their Buxtehude-Werke-Verzeichnis numbers, abbreviated BuxWV, after the catalogue published by Georg Karstädt.
• Marc Antoine Charpentier's works are referred to by the H or Hitchcock numbers after Hugh Wiley Hitchcock.
• George Frideric Handel's works are often designated by HWV (Händel-Werke-Verzeichnis) numbers as given in the Verzeichnis der Werke Georg Friedrich Händels by Bernd Baselt. (See this page at gfhandel.org for additional details.)
• Joseph Haydn's works are referred to by their Hob or Hoboken numbers after Anthony van Hoboken's 1957 classification. Hoboken assigned numbers to the string quartets, but these are generally still known by their opus numbers.
• Franz Liszt's works are referred to by their S or Searle numbers after Humphrey Searle's 1960s classification The Music of Liszt. Alternately, R is used to refer to Peter Raabe's 1931 reference Franz Liszt: Leben und Schaffen.
• Wolfgang Amadeus Mozart's opus numbers are particularly scattered and useless and are no longer used at all (for instance, there are two sets of violin sonatas both called Op. 1). His works are always referred to by their K or Köchel numbers, after Ludwig von Köchel. In continental Europe, the German abbreviation "KV" for Köchel-Verzeichnis is more common. See also: List of compositions by Wolfgang Amadeus Mozart
• Antonio Rosetti's works are usually given with catalog numbers by Sterling E. Murray, Chairman of the Department of Music History at West Chester University of Pennsylvania,[1] although older numbers from Oskar Kaul's 1912 Rosetti catalog sometimes appear as well. For example, Rosetti's popular "La Chasse" symphony is numbered as "Murray A20/Kaul I:18."
• Domenico Scarlatti's harpsichord works have two numbering systems: the L or Longo numbers after Alessandro Longo's edition for piano, and the K or Kirkpatrick numbers after Ralph Kirkpatrick's facsimile edition.
• Franz Schubert's works are referred to by their D or Deutsch numbers after Otto Erich Deutsch's catalogue. Schubert's opus numbers are very scattered, unchronological, and mostly posthumous, but a few of them are occasionally seen.
• Antonio Soler's keyboard sonatas are usually referred to by their R number, after the catalogue compiled by Father Samuel Rubio.
• Antonio Vivaldi's works are referred to by their RV or Ryom-Verzeichnis numbers after Peter Ryom's catalogue. Some of his works were published in opus sets, and these numbers are often still used as well.
• Richard Wagner's works are referred to by their WWV or Wagner-Werke-Verzeichnis numbers, which also include his non-musical work.

Karl Friedrich Abel (December 22, 1723 – June 20, 1787) was a German composer of the Classical era. ... Carl Philipp Emanuel Bach (March 8, 1714 – December 14, 1788) was a German musician and composer, the second of five sons of Johann Sebastian Bach and Maria Barbara Bach. ... 1905 (MCMV) was a common year starting on Sunday (link will display the full calendar). ... Johann Christian Bach (September 5, 1735 – January 1, 1782) was a composer of the Classical era, the eleventh and youngest son of Johann Sebastian Bach. ... Johann Sebastian Bach (pronounced ) (21 March 1685 O.S. – 28 July 1750 N.S.) was a prolific German composer and organist whose sacred and secular works for choir, orchestra and solo instruments drew together the strands of the Baroque period and brought it to its ultimate maturity. ... Bach-Werke-Verzeichnis (Bach Works Catalogue) is the numbering system used to identify musical works by Johann Sebastian Bach. ... Wolfgang Schmieder (1901–1990) was a German musicologist who, in 1950, published the BWV, or Bach-Werke-Verzeichnis (Bach Works Catalogue), a catalog of musical works by Johann Sebastian Bach. ... Wilhelm Friedemann Bach, in a portrait by Wilhelm Weitsch Wilhelm Friedemann Bach (November 22, 1710 – July 1, 1784) was the eldest, and by common repute the most gifted son, of Johann Sebastian Bach; a famous organist, a famous improvisor, and a complete master of counterpoint. ... Year 1913 (MCMXIII) was a common year starting on Wednesday (link will display the full calendar). ... Diderik Hansen Buxtehude (ca. ... Marc-Antoine Charpentier (1643 - February 24, 1704) was a French composer of the Baroque era. ... George Frideric Handel (23 February 1685 – 14 April 1759) was a German-born British Baroque composer who was a leading composer of concerti grossi, operas and oratorios. ... This article or section does not cite its references or sources. ... Anthony van Hoboken (March 23, 1887 - November 1, 1983) was a Dutch musicologist. ... Liszt redirects here. ... Humphrey Searle (August 26, 1915 - May 12, 1982) was a British composer. ... Mozart redirects here. ... A violin sonata is a musical composition for solo violin, often (but not always) accompanied by a piano or other keyboard instrument, or by figured bass in the Baroque. ... Portrait of von Köchel Ludwig Alois Ferdinand Ritter von Köchel (January 14, 1800 - June 3, 1877) was a musicologist, writer, composer, botanist and publisher. ... (For a list organized by genre, see List_of_compositions_by_Wolfgang_Amadeus_Mozart) The Köchel-Verzeichnis is a complete, chronological catalogue of compositions by Wolfgang Amadeus Mozart which was originally created by Ludwig von Köchel. ... This is a selective list of the works of Wolfgang Amadeus Mozart, for a complete list organized by Köchel number, see Köchel-Verzeichnis. ... Antonio Rosetti (c1750–1792) was a classical era composer, writing around the same time as Haydn and Mozart. ... 1912 (MCMXII) was a leap year starting on Monday in the Gregorian calendar (or a leap year starting on Tuesday in the 13-day-slower Julian calendar). ... Giuseppe Domenico Scarlatti (October 26, 1685 – July 23, 1757) was an Italian composer who spent much of his life in Spain and Portugal. ... Harpsichord in the Flemish style A harpsichord is any of a family of European keyboard instruments, including the large instrument currently called a harpsichord, but also the smaller virginals, the muselar virginals and the spinet. ... A grand piano, with the lid up. ... Ralph Kirkpatrick (* June 10, 1911 in Leominster, Massachusetts - † April 13, 1984 in Guilford, Connecticut) was a musician, musicologist and harpsichordist. ... Franz Peter Schubert (January 31, 1797 – November 19, 1828) was an Austrian composer. ... Otto Erich Deutsch (September 5, 1883 – November 23, 1967) was an Austrian musicologist. ... Antonio Francisco Javier José Soler Ramos (baptised December 3, 1729 - December 20, 1783) was a Spanish composer. ... Antonio Lucio Vivaldi (March 4, 1678, Venice–July 28 (or 27), 1741, Vienna), nicknamed Il Prete Rosso (The Red Priest), was a Venetian priest and baroque music composer, as well as a famous violinist. ... Wilhelm Richard Wagner (Leipzig, May 22, 1813 – Venice, February 13, 1883) was an influential German composer, conductor, music theorist, and essayist, primarily known for his operas (or music dramas as he later came to call them). ...

See also

• Category:Compositions by composer