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
K. S. Narayanaswamy K. S. Narayanaswamy K. S. Narayanaswamy, (full name Koduvayur Sivarama Iyer Narayanaswamy; 27 September 1914 – 1999) was a Carnatic veena exponent of the Thanjavur style, in which nuances and subtleties are given more importance over rhythm based acrobatics. He was awarded the Madras Music Academy's Sangeetha Kalanidhi in 1979. He was born on 27 September 1914 to Narayaniammal and Koduvayur Sivarama Iyer at Koduvayur in Palghat district in Kerala. He underwent initial training in Carnatic music under K.S. Krishna Iyer, his brother, between his seventh and fourteenth years. Later, he joined the Music College at Annamalai University in Chidambaram