No, it might not be the whole song as you probably would have expected,
but there was no cathegory for "main riff".
 I will post this nevertheless, and hope you will understand.
 My ears are not of the best,
but maybe you can figure out the rest yourself :)

The song Necropol Lit by Madder Mortem, taken from the album "Deadlands"(2002)


Starts with a bass intro in the same pattern as the guitar will
soon join in on, after a short slide from the 6th fret on the E-string(5th), to the 14th fret,
and back again. That pattern mentioned,
is for guitar, like this:
                              pmpmpm                            pmpmpmpm
b|-----------------------------------------------------------------------|
G|-----------------------------------------------------------------------|
D|-----------------------------------------------------------------------|
A|-----------------------------------------------------------------------|
E|--6-/7-7-7-6-/7-7-7-6-/7-7--7-7777-6-/7-7-7-6-/7-7-7-6-/7-7-7--0--0--0-|
B|---------------------------------------------------------------0--0--0-|

b|-----------------------------------------------------------------------|
G|-----------------------------------------------------------------------|
D|------------------------------------------------------------9--8--7----|
A|------------------------------------------------------------8--7--6----|
E|--6-/7-7-7-6-/7-7-7-6-/7-7--7--7-6-/7-7-7-6-/7-7-7-6-/7-7-7------------|
B|-----------------------------------------------------------------------|

b|-----------------------------------------------------------------------|
G|-----------------------------------------------------------------------|
D|-----------------------------------------------------------------------|
A|-----------------------------------------------------------------------|
E|--6-/7-7-7-6-/7-7-7-6-/7-7--7--7-6-/7-7-7-6-/7-7-7-6-/7-7-7----0--0--0-|
B|---------------------------------------------------------------0--0--0-|

b|-----------------------------------------------------------------------|
G|-----------------------------------------------------------------------|
D|------------------------------------------------------------9--8--7----|
A|------------------------------------------------------------8--7--6----|
E|--6-/7-7-7-6-/7-7-7-6-/7-7--7--7-6-/7-7-7-6-/7-7-7-6-/7-7-7------------|
B|-----------------------------------------------------------------------|

b|-----------------------------------------------------------------------|
G|-----------------------------------------------------------------------|
D|-----------------------------------------------------------------------|
A|-----------------------------------------------------------------------|
E|--6-/7-7-7-6-/7-7-7-6-/7-7--7--7-6--/7-7-7-6-/7-7-7-6-/7-7-7/10~-------|
B|-----------------------------------------------------------------------|

For corrections or comments, send them to petter666@live.com, and set subject to 
or "tabcomment".
Have fun.