Editing Opus number (section)

==Etymology==
In the [[Classical period (music)|classical period]], the Latin word ''opus'' ("work", "labour"), plural ''opera'', was used to identify, list, and catalogue a work of art.<ref>Lewis and Short, ''A Latin Dictionary'', s.v. "[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0059%3Aentry%3Dopus1 opus]".</ref>

By the 15th and 16th centuries, the word ''opus'' was used by Italian composers to denote a specific musical composition, and by German composers for collections of music.<ref>{{cite book|title=The New Grove Dictionary of Music and Musicians|volume=18|pages=503|isbn=0-333-60800-3|last1=Sadie|first1=Stanley|last2=Tyrrell|first2=John|date=2001|publisher=Grove}}</ref> In compositional practice, numbering musical works in chronological order dates from 17th-century Italy, especially [[Venice]]. In common usage, the word ''opus'' is used to describe the best work of an artist with the term ''[[Masterpiece|magnum opus]]''.<ref>''Oxford English Dictionary'', s.v. "opus". Retrieved from http://www.oed.com/view/Entry/132110.</ref>

In Latin, the words ''opus'' (singular) and ''opera'' (plural) are related to the words ''opera'' (singular) and ''operae'' (plural), which gave rise to the Italian words ''opera'' (singular) and ''opere'' (plural), likewise meaning "work". In contemporary English, the word ''opera'' has specifically come to denote the dramatic musical genres of [[opera]] or [[ballet]], which were developed in Italy.<ref>''Oxford English Dictionary'', s.v. "[http://www.oed.com/view/Entry/131729 opera, n. 1]", "[http://www.oed.com/view/Entry/131730 opera, n. 2]"</ref> As a result, the plural ''opera'' of ''opus'' tends to be avoided in English. In other languages such as German, however, it remains common.