Capo 5 (that's just the way I play it. It's easier for me to sing)
Verse:  
           Em   C               G               D
You oughta know. Tonight is the night to let it go
Em  C            G                D
Put on a show. I wanna see how you lose control...
Em        C                          D
So leave it behind, 'cause we have a night to get away
Em       C                          D
Come on and fly with me as we make our great escape.
Chorus:
Em                C
So baby don't worry, you are my only.
D                G               Em
You won't be lonely, even if the sky is falling down.
https://www.coveralia.com/acordes/down--feat--lil-wayne--jay-sean.php
C                 D
You'll be my only, no need to worry.
G                        Em
Baby are you down, down, down, down, down.
Em C     D                G                       Em
Down, down. Baby are you down, down, down, down, down.
Em C     D                G               Em
Down, down. Even if the sky is falling down.
Next verse, and so on, and so on.
Notes:
During the chorus, when G is the last chord, I usually walk the bass note down to 
Em. On the low E string, I play G, F#, E during the "down, down, down, down, down" 
part. You'll get it if you try it.