Petra

^{G G Em Em}
Verses:
^C Am ^D G ^Em D Em (Am may be a Am7)
^{Am C G D}
On the last C to G in the Verses:

Chorus:
^{Em B G D Em
G Em}
During the Solos it is the G Em Chords like in the intro which
fill the backround.
To start the solo....

Then just jam in the key of G
(blues scale at the 12th fret or open tuning)
One more important thing Bob throws in during the solo
^{G G E E}