Roma Violenta is one of more than 10 soundtracks scored by the legendarily prolific de Angelis brothers in 1975 alone. To my ear, the brothers de Angelis have one of the most recognizable sounds in all of Italian Cinemusic.
This soundtrack is complete with the typical variations on the main theme we come to expect with Italian soundtracks: altered tempo, addition and subtraction of instruments from track to track, etc. Roma Violenta in particular forays into bossa nova and blues territory on certain efforts, and the tandem are particularly deadly when they bust out the electric guitars.
The seven versions of "The Other Face" & "The Punitive Justice" are my particular favorites. Sample one here...
Then get the whole thing: