Where Did You Sleep Last Night

Riff:
1:    0
2: 0  0
3: x  x           2  2 2 0  0 0  4  4 4 4
4: 2  2           2  2 2 0  0 0  4  4 4 4 0       0 2
5: 2  2           0  0 0 x  x x  2  2 2 2 0       x 2
6: 0  0  0 0^2^3         3  3 3             2 2 2^3 0
the rest of the song is simply variations on that chord progression
 (Em A G5 B F#5 Em)