From “Sandese Aate Hai” to “Kal Ho Naa Ho” to “Papa Meri Jaan,” one voice has soundtracked three generations. This season, they will sing it back to him in the same arena.

 Picture a grandfather mouthing the opening line of “Sandese Aate Hai.” Beside him, his daughter waits for “Kal Ho Naa Ho.” Down the row, a teenager is already shouting for “Papa Meri Jaan.” Nobody planned it. A single voice made it happen over thirty years.