Joe Satriani started off as a guitar instructor, and his influence can still be heard in the chops of his famous pupils. The bluesy hymn “For the Love of God” reveals Steve Vai's debt to the guitar god's sweeping lyricism, while Metallica's Kirk Hammett applies Satriani's emphasis on finely etched chord progressions and arpeggios to grinding thrash epics like “For Whom the Bell Tolls.”