This is Shake it out, originally sang by Florece + The Machine.
I really like Glee's version so here it is for you all!
So this is the short version they sing on the show :)

capo on 3

( D )
Regrets collect like old friends
Here to relive your darkest moments
( G )
I can see no way, I can see no way
( D )
And all of the ghouls come out to play

Bm (x24432@1)        G (320003@1)                   DAnd (xx0232@1)every demon wants his pound of flesh
              A (x02220@1)                   BmBut (x24432@1)I like to keep some things to myself
           G (320003@1)           EmI (022000@1)like to keep my issues strong
             GIt's (320003@1)always darkest before the dawn

DAnd (xx0232@1)I've been a fool and I've been blind
                              GI (320003@1)can never leave the past behind
I can see no way, I can see no way
DI'm (xx0232@1)always dragging that horse around

Bm (x24432@1)             G (320003@1)                          DAnd (xx0232@1)our love is passed, it's such a mournful sound
                   A (x02220@1)                     BmTonight (x24432@1)I'm gonna bury that horse in the ground
              G (320003@1)            EmSo (022000@1)I like to keep my issues strong
                 GBut (320003@1)it's always darkest before the dawn

DShake (xx0232@1)it out, shake it out, shake it out, shake it out, ooh woaaah
Shake it out, shake it out, shake it out, shake it out, ooh woaaaah

GAnd (320003@1)it's hard to dance with a devil on your back
              DSo (xx0232@1)shake him off, oh woah

Bm (x24432@1)                           GAnd (320003@1)it's hard to dance with a devil on your back
D (xx0232@1)                                AAnd (x02220@1)given half the chance would I take any of it back
Bm (x24432@1)                        GIt's (320003@1)a final mess but it's left me so undone
Em (022000@1)          G (320003@1)              DIt's (xx0232@1)always darkest before the dawn

Bm (x24432@1)                          ALooking (x02220@1)for heaven, for the devil in me
Bm (x24432@1)                          ALooking (x02220@1)for heaven, for the devil in me
GWell (320003@1)what the hell I'm gonna let it happen to me

DShake (xx0232@1)it out, shake it out, shake it out, shake it out, ooh woaaah
Shake it out, shake it out, shake it out, shake it out, ooh woaaah

GAnd (320003@1)it's hard to dance with a devil on your back
DSo (xx0232@1)shake him off, oh woah

DShake (xx0232@1)it out, shake it out, shake it out, shake it out, ooh woaaah
Shake it out, shake it out, shake it out, shake it out, ooh woaaah
G (320003@1)               D (xx0232@1)End!