Sounds like theres an octave pedal on there. Or its just the bass. Here it is:

|---------------------------|
|---------------------------|
|6-6--6--------7--6-6-------|
|------9-9-9--9-------------|
|---------------------------|
|---------------------------|

And occasionally there's this:

|---------------------------|
|---------------------------|
|6-6--6------6-7--6-6-------|
|------9-9-9----------------|
|---------------------------|
|---------------------------|

Please rate and comment. Thnx for checkin out the tab.