Well-known southern composer M.S. Viswanathan, who has over 750 films to his credit, is battling for life at a private hospital in Chennai. MSV, as he's fondly called by the members of Tamil filmdom, is undergoing treatment at Fortis Malar hospital for old-age related ailments and breathing problem. "He's been undergoing treatment over the last few days. After initial treatment, he showed signs of recovery and was almost ready to be taken back home. But on Tuesday, his condition deteriorated and he had to be rushed to the ICU," a family source told IANS.  "His pulse had dropped and he was struggling to breathe," the source said. The source added that celebrities and close friends of Vishwanathan, 87, have already started paying visits. Popular for composing music in Tamil, Telugu and Malayalam industries, MSV started his career as composer for 1952 film Tamil "Panam" starring Sivaji Ganeshan. MSV is popular for his collaboration with fellow composer T.K. Ramamoorthy. The duo composed music for 86 Tamil films during their association of over a decade. Having started composing together in 1952, they split up in 1965. Some of their best films include "Paasamalar", "Sumaithaangi", "Server Sundaram", "Aayirathil Oruvan" and "Enga Veetu Pillai". Post the separation, MSV went on to become more successful. Viswanathan's solo hits include "Bama Vijayam", "Galatta Kalyanam", "Deivamagan", "Moondru Dheivangal", "Rickshawkarana, "Bharatha Vilas" and "Ulagam Sutrum Valibana. Popularly known as 'king of light music' (Mellisai Mannar), Vishwanathan has also worked in Malayalam films such as "Manthrakodi", "Babu Mon", "Ullasa Yathra" and "Amme Anupame". In Telugu, his compositions include "Tenali Ramakrishna", "Anthuleni Kathaa, "Idhi Katha Kaadu", "Aakali Rajyam" and "Maro Charitra". MSV and legendary filmmaker K. Balachander combination has produced several evergreen classics. Viswanathan's wife Janaki died in 2012. A year later, his best friend and composer T.K. Ramamurthy breathed his last. He is a recipient of Kalamamani and several other music awards.  With IANS