Intro - acoustic guitar

e-----------0----------------------------------------------------------
b---------4---4--------------------------------------------------------
g-------5-------5---- repeat ------------------------------------------
D-----7-----------7----------------------------------------------------
A---0---------------------------------8--------------------------------
E----------------------------------------------------------------------
Bass note changes to that F there ----^ but I don't know how it is 
being played maybe the guitar stays the same but the bass changes.
Somebody please tell me what to do.
This is what I play at the moment.

e-----------0---------------0---------------0--------------------------
b---------4---4-----------4---4-----------4---4-----------4---4--------
g-------5-------5-------5-------5-------5-------5-------5--------------
D-----7-----------7---7-----------7---7-----------7---7----------------
A---0---------------0---------------0---------------0-------0----------
E----------------------------------------------------------------------

By: Chris Johnson

e---------4-------7-------
b-------6-------6---------
g-----5-------5-----------
D---0-------x-------------