Album—Paranoid
Geezer Butler—Bassist
This whole song is just one riff over and over again.
Standard Tuning
b=bend
h=hammer—on
r=release bend

G|—————————7——————————|
D|——————7h9—————7b—r—5|
A|7——7—7—————5—5——————|
E|————————————————————|
I did a bass solo to this song, just do a repeating pentatonic scale and mix 
it up with some bends, hammer—ons, and pop—offs. Listen to the song for timing
:—) Hewo