You have no idea what you're talking about 
Unlike the silly kids who come to this site and put this false information everywhere, I actually KNOW as a FACT that Deep Purple, Black Sabbath and Led Zeppelin are HARD ROCK and NOT, by ANY MEANS AT ALL Heavy Metal. Sabbath and Deep Purple themselves have stated clearly many times that they are NOT HEAVY METAL. You are putting false information on this site, which is why this place is so unreliable. I am cleaning it up and making it more accurate. I would guess you are clearly much younger than me, I was brought up with these bands and I know better. The same with the stupid idea that "heavy metal" started in the late 60's. It DID NOT. It started in the mid 70's, I know, because I saw it form. Being the "forefather" of heavy metal does NOT MAKE YOU HEAVY METAL YOURSELF. It is you who is vandalising this website by putting false information on these bands pages after they have made clear several million times that they are NOT what everyone keeps saying they are. It is also easy to hear the difference. If I had the power, it would be people like YOU who would be blocked because you are making this site an unreliable source of information. IF you think you're right, ask the bands themselves. Then maybe you will change how you think. But I doubt it. Take care.