The riff is basically this all the way through:

Bb Bb/A Gm F Eb Dm F

I'd tend to suggest playing it higher up like so, at least at the start:

e | ------------------------------4-----1-------------- | 
B | ----6-----6-----3-----1-----5--5---3--3-----1------ | 
G | ---7--7--7--7--3--3--2--2--4-----2----------2------ | 
D | -8-----7-----5-----3-----3-------------3----------- | 
A | --------------------------------------------------- | 
E | --------------------------------------------------- | 

                       Bb  Bb/A Gm  F Eb Dm F
There was a day in the Grave   yard
                      Bb   
With helicopters overhead,
Bb/A    Gm         F  
I had a rose petal bed,
         Eb Dm         F
I had the    sun on my shoes,
   Bb Bb/A Gm F    Eb   Dm         F
And I knew, I knew, yeah I could see
        Bb       Bb/A    Gm           F  
That if you could make another one of you,
     Eb           Dm       F
Then you wouldn't give the other one to me, oh no
  Bb        Bb/A    Gm           F
If you could make another one of you,
    Eb            Dm       F
Then you wouldn't give the other one to me.

Bb Bb/A       Gm     F   
    If the conductor fucks up,
   Eb Dm              F            Bb
You   can't blame the symphony, so
Bb/A   Gm     F      Eb    
I won't blame you if you, 
   Dm        F
if you don't blame me,

Bb Bb/A Gm F Eb Dm F
                   You were doing something else that day x4

*humming* (repeat until end)