Opus number developed other catalogue-number systems; among them the "Bach-Werke-Verzeichnis" (BWV-number), and the "Köchel-Verzeichnis" (K- and KV -numbers) with which are organised the works of Johann Sebastian Bach and Wolfgang Amadeus Mozart, respectively. In the classical period, the Latin word "opus" ("work", "labour") was used to identify, list, and catalogue a work of art. 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. In compositional practise, numbering musical works in chronological order dates from 17th century Italy, especially Venice. In common usage, the
19th Century Drinking Horn 19th Century Drinking Horn On display in the Art Institute of Chicago, in the African Art and Indian Art of the Americas, is a 19th-century drinking horn. Originally from the Kuba Kingdom, the drinking horn is made out of wood, iron, and copper alloy. Drinking horns were usually a gift to the friends and family of kings or given to a warrior. The Kuba Kingdom, founded in the 17th century, is located in the Democratic Republic of Congo. It held nine provinces and chiefdoms were a part of that society. They were surrounded by other tribes such as the Yaka,