Rathnam had learned music from the age of seven under a guru called Ramalinga Aachari, and gave her first full-fledged concert in Sri Lanka.

She became popular with the film music directors of that era who had worked with her repeatedly and in that glorious period TVR rendered a staggering variety of challenging songs.

She also had a rare chance in Ponmudi (1950) by Modern Theatres when the music director the great G. Ramanathan had sung the songs by his composition, himself.

Others are G. Ramanathan, A. M. Rajah, M. M. Mariappa, T. A. Mothi, Thiruchi Loganathan, C. R. Subburaman, P. B. Sreenivas, S. V. Ramanan, V. J. Varma, V. T. Rajagopalan and S. V. Ponnusamy.

Others include P. Susheela, N. L. Ganasaraswathi, K. V. Janaki, T. R. Bhagirathi, Jikki, K. Jamuna Rani, Radha Jayalakshmi, A. G. Rathnamala, M. L. Vasanthakumari, L. R. Eswari, Soolamangalam Rajalakshmi, Swarnalatha and G. Kasthoori.