Tuning - tune down a whole tone to DGCFAd 

d|--------------------------------------------------| 
A|---3--3--3-3-3-3----3--3--3-3-3-3-3--3------------| 
F|---0--0--0-b42-0----0--0--0-0-0-0-2p0-------------| repeat and bung the next 
C|---0--0--0-------0h2-----------------0h2----------| slightly different one in 
G|-----------------------3--3-3-3-3-----------------| every time he is just about 
D|--------------------------------------------------| to sing. 

d|--------------------------------------------------| 
A|--3--3--3-3-3-3----3--3--3-3-3--3-3-3-3-----------| 
F|--0--0--0-b42-0----0--0--0-0-2--2-2-0-------------| 
C|--0--0--0-------0h2----------0-0-0-0----4---------| 
G|----------------------3--3-3----------------------| 
D|--------------------------------------------------| 

just muck around with that, add in your own variations. 
matt does it differently every time and i couldnt be bothered tabbing them all.