This is the synth line that goes over the piano arrangement for the 
whole song. What you need to do, is play the first note only and 
use a delay repeat to achieve the second note. If you dont have 
a delay pedal, just play both notes, but it sounds so much better 
when you're holding the note and it's repeating behind what your playing. 

e |-11-(11)--------------------|-9-(9)--------------------|
B |-----------12-(12)--9--(9)--|---------9-(9)------------|
G |----------------------------|-----------------11-(11)--|
D |----------------------------|--------------------------|
A |----------------------------|--------------------------|
E |----------------------------|--------------------------|

e |------------11-(11)-----------|-12-(12)-----|
B |--12-(12)-------------9-(9)---|-------------|
G |------------------------------|-------------|
D |------------------------------|-------------|
A |------------------------------|-------------|
E |------------------------------|-------------|

I've sort of messed around trying to figure out the piano part 
and it seems that this arrangement works pretty well.

NOTE--theres four chords and they all last for one bar.

G#m   B   G#m  E (half barre)
 4    7    4   7
 4    7    4   9
 4    8    4   9
 6    9    6   9
 6    9    6   7
 4    7    4   x
     
Keep in mind, these chords are basically just to keep you a 
little bit busier. The actual piano just basically follows the 
G#m the whole time and adlibs around it. This a gorgeous song, 
and theres probably a lot more that could be done on it, but 
I'll leave that to your creative ventures. 

Have fun!