riff one:
G|------------------------------------------|
D|------------------------------------------|
A|-8--10---10----8---7--8--10---10----8---7-|
E|------------------------------------------|

G|------------------------------------------|
D|-8--10---10----8---7--8--10---10----8---7-|
A|------------------------------------------|
E|------------------------------------------|


  riff one variation:
G|--------------------------------------10--------------|
D|-8--10---10----8---7--8--10---10-10/12-----1210-8-7--|
A|------------------------------------------------------|
E|------------------------------------------------------|


  riff two:
G|------------------------------------------|
D|------------------------------------------|
A|-8--10---10----8---7--8--10---10----8---7-|
E|------------------------------------------|

G|-----------------10------------------------------------|
D|-8--10---10-10/12-----1210-8-7--8--10----10--12-10-8-|
A|-------------------------------------------------------|
E|-------------------------------------------------------|