As a musician, he started as a bass guitarist and switched to lead guitar, introducing Rock and Hard Rock to Sri Lankan audiences. His departure to Bourneville, USA at the height of his popularity in the late 1970s created a void in the music scene in Sri Lanka that lasted for sometime. The sheer number of rock music festivals and concerts Navaratnam conducted is yet to be matched by contemporary rock groups on the island. Kumar remains regarded as a pioneer of Sri Lankan Western music.