What is that noise?

I'm sure when you see John dancing you often wonder: What is Crazy Robertson listening to on that boombox. It's hard to hear the music while you are driving by because traffic is noisy and unless you are in bumper to bumper or you are a Madman at name that tune it's tough to decipher the song. I mean he wears skates so you think he's doing disco, nope, he's metal. His choreographics and brilliance on wheels are all based on the sounds of powerful, drum-heavy rock n' roll. I was talking music with John lately and he revealed what he feels is the greatest album of all time. He answered with the quickness so I assume he's pretty down with this album...
John's favorite album:

Drumroll please... .. ..
Black Sabbath Vol. 4
other 5 star albums on John's list:
Jimi Hendrix- Fillmore East

Ted Nugent- Double Live Gonzo
More lists by John Jermien to come...