Here's the song Yaar Yaar Sivam from the movie Anbe Sivam. Set to tune by Vidyasagar this song is an example of how a simple song, both in lyrics and tune, can become the soul of a movie. The lyrics extends the rationalist thoughts which runs through out the movie. Of course, the movie by itself is a classic. I have not sung the chorus part of the song so it might sound a bit different from the original.