The music launch of Mani Ratnam's Hindi film "Guru" set a new trend in Bollywood with superstar Amitabh Bachchan hosting the event here Sunday.

Amitabh called son Abhiskeh Bachchan, the film's lead actor, on stage and asked him: "What was your reaction when Mani Ratnam offered you the role?" To which Abhishek said: "My reaction was, thank god he called up again."

After scenes from "Guru" were shown, Amitabh called the film's heroine Aishwarya Rai, who wore a white and gold sari, and actor R. Madhavan on stage.

Asked about her role, Aishwarya said: "I play Abhishek's wife. I am his emotional strength, his moral support, his everything which a wife does."

Madhavan said he "was very delighted" to work with the ace Tamil director again.

Amitabh then called lyricist Gulzar and music composer A.R. Rehman together on the stage and asked them what came first, the music or the lyrics?

Gulzar said, "We both worked together." Speaking about the film Abhishek Bachchan told CNN-IBN, "Guru has been a very challenging film. A very tough film to do. I hope it is rewarded. More so for Mani because he has worked very hard on it. He is just truly a genius and deserves every bit of credit that he gets."

The film also stars Vidya Balan, in a small and pivotal role along with Mahadevan . Other credited cast includes Mallika Sherawat and Mithun Chakravarty.