C (3rd), Fm (1st), Am (5th) and Gm (3rd)
In between these chords at certain points in the song I play this:
DO FAm LAm SOLm
e|-------------|--------------|--------------|------------------|
B|-3--5--6--5--|--3--5--6--8--|--8--6--5--6--|--8--6--5--6\5----|
G|-------------|--------------|--------------|---------------5--|
D|-------------|--------------|--------------|------------------|
A|-------------|--------------|--------------|------------------|
E|-------------|--------------|--------------|------------------|
|