Bass Tab:
(Played constantly over the whole song)

G|----------------------------------|
D|----------------------------------|
A|-3-5-5-6-5-5-3-5-5-6-6----|
E|----------------------------------|

(play after every third time)
G|----------------------------------|
D|----------------------------------|
A|-3-5-5-6-5-5-3-5-5-6666--|
E|----------------------------------|