This great Trance song used is called 'When Tomorrow Never Comes' by Beat Service with Cathy Burton - from the official A State Of Trance 2011 Album. For the song I chose here, the music actually makes sense with what it is happening on screen; since the lyrics manage to convey the characters' feelings. I wanted a track that has energy and has a different sound i.e. feel than the background score (which is just a sadder instrumental of the Title song).
Especially note when Shahrukh leaves the hospital, frantically runs through the street and then stops for breath; the tempo of the song I used suits it beautifully and you can actually hear a 'Heartbeat' in the track if listened carefully.
The title of this song I used is 'When Tomorrow Never Comes' that ironically enough is similar to 'Kal Ho Naa' Ho in English; which literally can means 'Tomorrow May or May Not Be'.
The song lyrics here can be seen through the eyes and mind of the three main characters' perspective: how they're heartbroken over Aman's illness although it affects them differently.