(bass)
Riff 1:
---------------------------------
[---------------------------------] repeat
[---------------------------6--4--] several times
--0--0----0-4-5----7-----7-------
Riff 2:
------------------------------------------------------------
[------------------------------------------------------------] back to
[--7--7-5--5-5------4--4-3--3-3------------------7--4--------] Riff 1
-----------------------------------7--7-7--7----------7--4--