[3] Vaidyanathan started his career as an Assistant music director to G. K. Venkatesh and composed the score for over 170 films in languages including Tamil and Kannada.

His notable works include Pesum Padam, Ezhavathu Manithan, Dasaratham and Marupakkam in Tamil and Aparichita, Kubi Matthu Iyala, Ondu Mutthina Kathe in Kannada.

He was one of the best music arrangers in the country and was known for his use of rare and unknown instruments, subtly mixing sounds from the mandolin, flute and violin with various folk percussion instruments before the advent of present-day technological advances in sound mixing.

One catchy and enduring composition of his would be, the Opening and Closing Score 'Thaana na nana' of Shankar Nag's Malgudi Days (TV series).

In 2003, the government of Tamil Nadu awarded Vaidyanathan with the Kalaimamani for his contributions to cinema.