Gender-bender?
One of my favorite songs, "POttu Vaitha Kadhal Thittam" originally sung by Kamal in the film SingAra VElan is being performed by two girls in the Toronto show. The lead singer (forgot her name, she performed in the Chennai show as well) sounds quite good and seems to enjoy the song. Looks like the show is going to have more such surprises... Perhaps the 'surprise' singer is Kamal himself?