Not the original Key but its easy to sing like this, can easily put a tune to it 
if you dont want to rap it :) hope you enjoy! Optional Capo 3

C (x32010@1)C (x32010@1)                     DAnd (xx0232@1)when I'm gone, just carry on, don't mourn
  EmRejoice (022000@1)every time you hear the sound of my voice
              C (x32010@1)                          DJust (xx0232@1)know that I'm looking down on you smiling
             EmAnd (022000@1)I didn't feel a thing, So baby don't feel my pain

Just smile back
C (x32010@1)                     DAnd (xx0232@1)when I'm gone, just carry on, don't mourn
  Em (022000@1)   
Rejoice every time you hear the sound of my voice
              CJust (x32010@1)know that I'm looking down on you smiling
             Em (022000@1)                                DAnd (xx0232@1)I didn't feel a thing, So baby don't feel no pain

Just smile back...