O.S. Vaidyanathan - or Arun, as he is more popularly known is a Carnatic music vocalist. He began his music training under his father O.V. Subramaniam. He qualified in Alankar Purna from Gandharva Mahavidyalaya and topped the Sangeetha Shironmani course in Carnatic Music conducted by the faculty of Music and Fine Arts of Delhi University. 

He is appreciated for his close grasp of classical grammar, energetic rendering as well as his versatile repertoire and lively stage presence. He has given concerts at India International Centre, Rasika Ranjini Sabha, Krishna Gana Sabha, Haridas Sammelan, Mylapore Fine Arts Club, Kalarasana Chennai, Badri Kedar Utsav, ICCR's, National Centre for Performing Arts and Qutab Festival, in India among others. Internationally, he has performed at Sanskriti Festival, London, World Adelaide Festival, International Delima Festival, Mauritius, 45th Independence Day at Kabul, Afghanistan, United Nations, Singapore Art Festival. He has also worked on various collaborative projects with jazz musicians. 

A prolific composer, Arun has composed music for music productions, videos, documentaries and dance ballets. He is also known for a choir that he has established.

Among the numerous awards that Arun has received are Culture India Award (1989), Best Vocalist award from Indian Fine Arts Society (1997-98), Best Pallavi award from Krishna Gana Sabha, Best Vocalist/Alapana award from Music Academy (2000-01) and the title ‘Brahma Gana Samrat’ by the Brahma Gana Sabha.