Even though there's no real bass guitar through most of the song, I still thought I'd 
tab it anyway.  This pretty much what the left hand keyboard plays in the intro:

|--------------------------------------------------------------------|
|--4-4-4-4--4-4-4-4-4--4---------------------------------------------|
|------------------------4-4-4-4--4-4-4-4-4--4-6-6-6-6--6------------|
|---------------------------------------------------------7-7-7-7----|

And the chorus is something like this.  Same basic pattern, just hold each note.

|--------------------------------------------------------------------|
|--4-----------------------------------------------------------------|
|-----------4--------6----------------4------------------------------|
|----------------------------7---------------------------------------|

Then there's a bass line before/during the rap verse, starts at about 3:01, then repeats 
at 3:23

|-----------------------------------------------------------------------|
|------------------------------------------------------10-12-10---------|
|-----8--10-12-10--8--10-----7--10-12-10--8--7--8--12------------12--8--|
|-10----------------------8---------------------------------------------|

|-----------------------------------------------------------------------|
|-----------------------------------------------------------------------|
|----7--10-12-10--8--7--------------------------------------------------|
|-8---------------------8-----------------------------------------------|