E|----------------------------|
B|----------------------------|
G|----------------------------|
D|--0--0--0--3--3--3--4--4--4-|
A|--0--0--0--3--3--3--4--4--4-|
E|--0--0--0--3--3--3--4--4--4-|

  This is the main riff and occassionally there is a variation where you
  simply play this riff...but only with the Low D string and then gradually
  bring in the A and the D string.


  The other part of the riff goes like this:

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


  Then there is this descent:

E|--7--7--6--6--5--5--4--4--3--3--2--4b--|
B|---------------------------------------|
G|---------------------------------------|
D|---------------------------------------|
A|---------------------------------------|
E|---------------------------------------|