Just repeat this structure :)

G                  F         G
Far over the misty mountains cold.
G           Dm                 G           
To dungeons deep, and caverns old.
G                         F   G
The pines were roaring on the height.
G              Dm             A
The winds were moaning in the night.
A            Dm              A     
The fire was red, it flaming spread.
A              A#               G  
The trees like torches blazed with light.

The chords are bared so it is not the ordinary pop chord but rock chords :) Hope 
there is no missunderstanding :)
I have a slightly modified version but I dont know what the chord name is of that 
G-chord but an ordinary G works well too :)