I still consider Watchtower and Voivod pretty extreme.

80's Iron Maiden? 70's Judas Priest? Black Sabbath? Are you telling me these examples are just as heavy as Master of Puppets? I guarantee the average music listener would find them more musical and less extreme than MoP.

Hard call.

Thrash can be extreme or not extreme. So can death and black metal. There's death&roll bands and folk/indie/shoegaze BM that's not particularly aggressive but is still part of a genre that, collectively, is called "extreme metal".

Thrash resides firmly on the border between traditional and extreme. For example, Metallica, Megadeth, Anthrax, Heathen, Suicidal Tendencies, etc. are pretty hard to classify as "extreme" by most standards. The fact that most of those bands found some, or a lot, of commercial success speaks to that. From my experience, most casual or non-metalheads can hang with bands like that just fine. On the flip-side, it's hard to then also say that Slayer, early Kreator, Sodom, Demolition Hammer, or Warbringer aren't extreme. Non-metal fans would have a much harder time with those groups than they would the former.

All black metal is extreme metal. If it's not particularly aggressive or extreme then it's not black metal, it's something else.

Like many before me have said, it all depends on what band we're talking about. There's nothing extreme about Ride the Lightning or Master of Puppets. They're more aggressive, overall, than Maiden or Sabbath? Yeah. But they're still way more "easy listening" than Reign in Blood, Schizophrenia, Laws of the Scourge, etc. Most early Death Metal records sound like Thrash Metal for a reason: Thrash is the main root for extreme metal in general, yet for this very reason it's very transitional.

I would say that FFWF and Damage Inc could fall into extreme category. Agreed with the rest though.

Albums like Reign in Blood, Eternal Devastation, Pleasure to Kill, Darkness Descends, Spectrum of Death, Idolatry, Violent Restitution, Epidemic of Violence, Within Suffering, Decameron, Slaughter in the Vatican, Ritually Abused are what I'd call "extreme thrash". It ain't death metal but it's really fucking heavy, fast, and brutal anyway.

I would say that FFWF and Damage Inc could fall into extreme category. Agreed with the rest though.

I absolutely agree about Fight Fire With Fire. It's ridiculously heavy and James' vocal performance isn't THAT much different from Sodom/Kreator in my opinion. Having said that, that's ONE track.

Historically speaking, thrash was not EM because, in the thrash era, an EM term was not viewed as necessary, hence it was not invented. Yes, there are thrash bands and albums which sound close to DM, such as Pleasure to Kill and Reign in Blood. Historically, they came before EM so the term can't really be applied to them. We can't apply the term "motor vehicle" to horse-and-carts or "tower blocks" (a British term) to walk-up 1930s apartments. From the pure musical standpoint, too, the albums I mentioned had shouted or yelled vocals, which remains very different from the DM growl.

Mille Petrozza does sound quite growly at times on Pleasure To Kill (Under the Gullotine for example).

I’d still consider Slayer circa Hell Awaits/RIB Extreme Metal despite the more yelling vocals. He sounds more aggressive than say a Hetfield and literally EVERYTHING else about that record is extreme and completely un-radio friendly.

Yes, thrash is extreme metal. I don't really understand why this is even a debate? Because the vocals aren't growls or black metal shrieks? No blast beats? There's still double bass drumming, a cornerstone of extreme metal music, fast and aggressive riffs, often aggressive vocals. The most extreme thrash bands are heavier than most death metal and black metal imo.

Yes, thrash is extreme metal. I don't really understand why this is even a debate? Because the vocals aren't growls or black metal shrieks? No blast beats? There's still double bass drumming, a cornerstone of extreme metal music, fast and aggressive riffs, often aggressive vocals. The most extreme thrash bands are heavier than most death metal and black metal imo.

No offense, but your opinion is in the minority. It's just never been considered extreme metal, and not only because of the vocals, but the general sound.

Really listen to thrash guitar and how different it sounds from death metal, black metal or grindcore guitar. It's just not the same.

Oh agreed. Take Cynic for example. Certainly Hell Awaits is more extreme than Focus, despite the former being considered a death metal classic (though Cynic were certainly more than just plain DM).

This is truly the most pedantic debate ever. How about this. To some, Slayer is extreme. To others, not so much. Cool beans?