Found this gem from a blog maintained from an acquaintance who writes for the Illayaraja thread community in Orkut:
http://ragamanjari.blogspot.com/
His blog (second one from the top) succintly analayses "Madhu Malargal" nice sweet song with MV and Janaki
Susheela really breaks your heart with "Magane" even with the elderly voice her words are so weighted with sorrow
My fave is "Malligai Poovukul" with MV and Janaki again...I like the loud expressive beginning and the softness that follows
the crescendo of their voices up a scale and the interchange of their voices at the same time...very hard to achieve and still not make it sound cacophonous. Janaki's voice is so teasing in this song...the electric guitar is a nice surprise right in the middle...not expected at all...the flute again softens...
http://www.raaga.com/channels/tamil/album/T0002785.html