नीला आसमाँ सो गया (female)

This is the Lata Mangeshkar version that sings about lost love.

"The night got killed when the moon disappeared in [my] tears.
Loneliness is what fills in [the rest of my] life"

The music punctuates the narration of the story nicely to bring out the emotion. You can relish the male version here.

नीला आसमाँ सो गया (male)

It is rather rare that an actor or an actress also provides the singing based on a classical raag. Amitabh Bachchan does this well here. A musical pun, in a female voice later in the story, recounts the heartbreak.