Just heard that on TV for the first time. I'm pretty sure that the tuning is drop A, meaning the low E string is downtuned to A while the others stay in standard tuning. The result is AADGBE. Intro riff/main riff : E|---------------------------------------------------------------------| B|---------------------------------------------------------------------| G|---------------------------------------------------------------------| D|---------------------------------------------------------------------| A|-------------10-10-10-------10-10-10---------------------------------| A|-0-0-0-7-7-7----------7-7-7----------3h5-5-5-5p3-3-3-3h5-5-5-5p3-3-3-|