Guitar Prasanna's experiment with time signature

Guitarist Prasanna commented on his Facebook wall about his experiment with time signature in his debut film as a composer:

Some of you asked me what this earlier post of mine was all about -(3/4, 3 and half/4, 3/4, 4/4), (3/4, 3 and half/4, 3/4, 4/4), (4 and half/4, 4/4), (4 and half/4, 3 and half/4), (4/4, 4/4, 4/4), 2/4 - These are the time signatures for each bar of the 'Charanam' of the song 'Oru Kural' that I composed for the film 'Vazhakku Enn 18/9' - And I GOT AWAY WITH IT in my very first song in a mainstrea...m Tamil film and I am so glad the song has got so much attention too. Thanks to the Tamil film audiences for the overwhelming support for the film and the music and for telling me its ok to not dumb things down! For those of you who want to listen/count, here it is!

Interesting experiment! It is tough for me to follow the time signature with no accompaniments. I haven't seen the film yet, so I am not sure why he chose not to have any accompaniments.

UPDATE (July 12 2012): In his recent interview, Prasanna says that having no accompaniments was the Director's idea.
... it turned out in the end that the only song in the film ‘Oru kural ketkuthu penne’ not only didn’t have any ‘electronic programmed machine stuff’, it didn’t have any instruments at all! Maybe Balaji took my ‘acousticism’ even further than me!  Just kidding! But I am glad that the song has been highly acclaimed  a song with just voice and no instruments and it was entirely Balaji’s idea. 
Don't forget to the listen to the Theme Music from the film which is an instrumental version of this song.

This one has some nice guitar and drums accompaniment and the main melody is hummed by a female vocalist (any idea who the singer is?).