And Shoojit Sircar is anxious to meet them. "I've read so many of Lataji's and Ashaji's observations on Kishore-da, " says Shoojit. "They'd be invaluable in giving shape to the bio-pic.
Unfortunately meeting the two living legends of the singing world is not easy, not for a director who's just one-film old.
"Fortunately for me, the Ganguly family --wife Leena Chandavarkarji, sons Amit and Sumeet Kumar-- have opened their hearts and homes to me.I don't know why. Partly because I'm Bengali. They've shared their rarest of experiences with Kishore-da, and unreleased songs and rare footage from his films."
Shoojit intends to incorporate images, songs and the voice of the real Kishore Kumar in the movie based on his life.
However he's amused and perturbed by the names that were willy-nilly hurled in the press about the principal casting.
"Please, it's not Aamir, Shah Rukh or Hrithik Roshan playing Kishore Kumar. I don't know where they got these names from. I'll first complete the script before I even think of whom to cast.
For all we know, we may cast a complete newcomers, "says the reticent director r whose latest film Shoebite has got itself into a bit of a controversy Shoojit Sircar who's working relentlessly on his ambitious Kishore Kumar bio-pic has chanced upon some startling facts on the legendary eccentric genius.
Do any of Kishore Kumar's fans know he had partly financed Satyajit Ray's career-making directorial debut Pather Panchali? A fact Kishore never tired of reminding Ray about whenever they bumped into one another in Kolkata.
Says Sircar, "Kishore Kumar never stopped preening about this fact to close friends, 'Do you know India's greatest film Pather Panchali could've never been made if it wasn't for me' He loved to see himself as a patron of the fine arts. In fact some of the films thar Kishore Kumar directed like Door Gagan Ki Chaon Mein reflected the sensitivities of Ray."
Thanks to the active and unconditional support of the Ganguly family Sircar's bio-pic which he starts shooting in the middle of next year, will reflect the unknown side of Kishore Kumar.
"We've seen enough of the eccentric side. Now we'll see the sensitive side of the man who sang numbers as deeply moving as Chingari koi bhadke and Mere naina sawan bhadow and who patronized Satyajit Ray's cinema."
In fact it's not just the singing-maverick's family which has opened its doors to Shoojit's ambitious project. Apparently even the Ray family is all for it.