It is played in some open tuning but special chords are provided to make it sound alike.
eg. There is the normal C chord you play,
and there is a special C2 chord where you just add G note to make it sound heavier.

[Special Chords Used] 
(Use these chords when given)
                        C2     C/B    Em5     C7M
C2  - 332010        eb|---0------0------0-------0-------|
C/B - x20010   or   Bb|---1------1------5-------0-------|
Em5 - 035050        Gb|---0------0------0-------0-------|
C7M - 032000        Db|---2------0------5-------2-------|
                    Ab|---3------2------3-------3-------|
                    Eb|---3------x------0-------0-------|

[Intro]
C - Am - G - F

[Verse 1]
C               Am            G          F
Can you help me out, can you lend me a hand?
F
It's safe to say that I'm stuck again
C                    Am           G
Trapped between this life and the light
       F
I just can't figure out, how to make it right...
  Am             G
A thousand times before
     Am                            F
I've wondered if there's something more... something more...

[Chorus]
                  C2                  C/B
I feel it's gonna rain like this for days
                F                 Em5
So let it rain down and wash everything away
            C2                    C/B
I hope that tomorrow the sun will shine
            F                      C7M
With every tomorrow comes another life...

[Bridge]
                  C      Am       G        F       
I feel it's gonna rain,       for days and days

(I feel it's gonna rain)

[Verse 2]
C                 Am           G        F
I tried to figure out, I can't understand...
F
What it means... to be whole again...
C                   Am            G        F
Trapped between the truth and the consequence
F
Nothing's real, nothing's making sense...
  Am             G
A thousand times before
     Am                            F
I've wondered if there's something more... something more...

[Chorus]
                  C2                  C/B
I feel it's gonna rain like this for days
                F                       Em5
So let it rain down and wash everything away
              C2                  C/B
I hope that tomorrow the sun will shine
                      F                 Em5              F             G
I feel it's going to rain like this... rain like this... rain like this...

[Verse 3]
Am    F     C2           G
Fall down, wash away my yesterdays
Am    F       C2                G
Fall down, so let the rain fall down on me...

[Chorus]
                  C2                  C/B
I feel it's gonna rain like this for days
             F                        Em5
Let it rain down and wash everything away
              C2                  C/B
I hope that tomorrow the sun will shine
                     F                  Em5
I feel it's going to rain like this... rain like this...

[Outro/Chorus]
                C2     C/B
So let the rain fall...
                   F            Em5
I feel it's gonna rain this... rain like this...
                C2    C/B
So let the rain fall down...
                   F
I feel it's gonna rain like this...
                   C7M
I feel it's gonna rain.