Doing a speech on Metal, would love help

Thursday I'm giving a brief overview on metal and subgenres with a focus on death, black, prog and power metal because I think they are the easiest to explain and the most fun to talk about and to make fun of. WHAT SHOULD I INCLUDE? AND GIVE ME SOME SOURCES. nothing to lengthy, need to fit this in under 7 minutes. pictures are nice too. you can give me your definitions of the genres as long as they are accurate and have things to back it up with.

My advice? Don't do it on metal.

Death
Death
Cannibal Corpse
Deicide

Black
Bathory
Mayhem
Burzum
Darkthrone

Talk about Sabbath as usual.

Progressive metal, I guess you could talk about the trials and tribulations of Dream Theater, but I don't know - it feels like the overview would be skating too close to the surface. I can't imagine that'd be representative of metal at large.

I once wrote an English assignment about the psychosis of the first wave of Norwegian black metal. I believe the reason it went over so well was a specified thesis.

Maybe you can do your presentation on the stage presence of bands. That'd be fun. And then throw in how important guitar solos are to pump up the crowd and whathaveyou.

im not really going to be focusing on bands, more on the differences in genres and kind of hinting at the elitism in the scene in some cases. more of an overview going over misconceptions and defining subgenres. Honestly, I would have prefered to not to it on metal, but i couldn't figure out any other i wanted to talk about in time, and this seemed the most fun idea.

the bands i have mentioned so far are almost you're list- death, possessed, mayhem, burzum. sabbath i haven't even mentioned at all haha, because they don't really fit into the categories i arbitrarily picked out, but I should probably throw them in at some point. the hard part will be keeping it all under 7 minutes which is why im trying not to go into detail about bands as much

Less is more dude. Don't mention too many bands nobody will be able to follow if you go into detail on too many

Why not focus on two that are successful at whatever it is you're arguing - or why one is better than the other but both are highly touted

i wasn't even going to do that, just mostly describe the characteristics of each genre which I would like clarification.