John Mayer's cover of Beyonce's 'Xo'.
Played on his tour in Australia, apparently the first time he's performed it.
Only had a few versions to listen to, and this may be a bit rough but its around 
the mark.

***CAPO 2***

| C Am F | are the chords used in Beyonce's version, 
however it seems John plays it slightly differently (in verse) in his cover:

   C             Cadd9 (not sure*)            F                   Am

e |--0--|            |--3--|               |--3--|              |--0--| 
b |--1--|            |--1--|               |--1--|              |--1--| 
g |--0--|            |--0--|               |--2--|              |--2--| 
D |--2--|            |--2--|               |--3--|              |--2--| 
A |--3--|            |--3--|               |--3--|              |--0--| 
E |--x--|            |--x--|               |--x--|              |--x--| 

[Verse 1]
               C
Your love is bright as ever
     Cadd9
Even in the shadows
    F
Baby kiss me
                             C
Before they turn the lights out
       C
Your heart is glowing
        Cadd9
And I'm crashing into you
    F
Baby kiss me (kiss me)
                             C
Before they turn the lights out

Before they turn the lights out

Baby love me lights out

[Pre-Chorus]
C
In the darkest night hour
Am
I'll search through the crowd
             F
your face is all that I see
G
I'll give you everything
                       C
Baby love me lights out

Baby love me lights out

[Verse 2]
               C
We don't have forever
     Cadd9
Baby daylight's wasting
    F
You better kiss me
                             C
Before our time is run out

       C
Nobody sees what we see
        Cadd9
They're just hopelessly gazing
    F
Baby take me (take me)
                             C
Before they turn the lights out
Before time is run out
Baby love me lights out

[Pre-Chorus]
C
In the darkest night hour
Am
Search through the crowd
             F
Your face is all that I see
G
I'll give you everything
                       C
Baby love me lights out
Baby love me lights out
Oooh you can turn my lights out

[Chorus]
C
I love it like XO
C
You love me like XO
Am
You kill me girl XO
Am
You love me like XO
F
All that I see
       G
Give me everything
                  C
Baby love me lights out
Baby love me lights out
You can turn my lights out

*Harmonica solo*
Continue same chord progression

[Pre-Chorus]
C
In the darkest night I'll
Am
Search through the crowd
             F
Your face is all that I see
G
I'll give you everything
                       C
Baby love me lights out
Baby love me lights out
Oooh you can turn my lights out

来源：www.ultimate-guitar.com