The main riff is an Amaj with a pinky drop to the suspended fourth every now and again.  
It's pretty much the whole song...

e | ------0--0-0-----------0--0-0----------------------- | 
B | --2222222222223322-2222222222223322----------------- | 
G | --2222222222222222-2222222222222222----------------- | 
D | --2222-22-2-222222-2222-22-2-222222----------------- | 
A | --0----------------0-------------------------------- | 
E | ---------------------------------------------------- | 

Alternately:

e | ---------------------------------------------------- | 
B | ---------------------------------------------------- | 
G | --6666966969667766-6666966969667766----------------- | 
D | --7777777777777777-7777777777777777----------------- | 
A | --0----------------0-------------------------------- | 
E | ---------------------------------------------------- | 

NOTE: The actual verses are almost entirely this A progression, but it lacks depth when 
you're playing it alone on the acoustic.  I like to throw around the F#m when it feels 
natural, as below, and palm mute until the chorus:

         A5
When you step in the room they won't be holding me down
          F#5
All these demons in my head c'mon let's kill 'em with sound
            A5
You see I'm beggin' that you take me and you never look back
               F#5
That's why I'm crying to a wall hoping that you come out

A5
Hey...I don't wanna wake up from this
                            F#5
I cannot afford to forget

The feeling of your arms, they hold me
                                      A5
The power of your skin, it's lovely

You provoke a man to bow down
                                F#5
I get on my knees and cry out
                            E5
"Everything I have is yours now"

               D5
So the time is now
             E5
Don't let me down
               D5
Oh the time is now
                    E5
Please don't let me down


Chorus:
    A5                      A5     F#5
Get higher, and higher, and higher
        D5                  A5
When my back's against the wall
           D5                   A5
You're the hand that breaks my fall
                             A5     F#5
Climb higher, and higher, and higher
        D5                  A5
When my back's against the wall
           D5                   A5
You're the hand that breaks my fall


***Lather, rinse, repeat

-JVV