This is what it comes down to. It's not our website. I can't think of any good examples right now except for Coma Cluster Void. They are obviously, undoubtedly, unquestionably a metal band, and way heavier and "more metal" than plenty of other bands that are on here. I can only imagine the reason they aren't on here is because one the mods is "too metal" to accept them, or they simply don't like them. Whatever, at the end of the day it just lowers the sites credibility and integrity when it comes to being the end-all be-all encyclopedia of metal bands.

the reason why there is this ambiguous border between metal is most of all not because specific riffs are or arent metal but because bands combine metal and non metal riffs in a certain manner.
Makiladoras is death metal /crust punk i submitted to MA a while ago and they did this actually pretty unique thing of having literally 50% metal songs and 50% non metal songs pretty clearly distinct from each other. I haven't seen any other band do this. when it comes to borderline bands, instead they combine the metal and non metal in the songs themselves so you end up with stuff like slipknot where they have a death metal riff for like 20% of the songs run length but something decidedly not metal for the rest of it.

Eh, you can trace a lot of black metal back to Bathory, Celtic Frost, etc... that is also what I'd consider classic enough to be genre-forming. And they came from Sabbath and various other weird influences forming back in the 80s. I think it's all connected and you can hear it if you listen to enough. It isn't so mysterious.

Power metal, yeah, some of it can be quite light for metal, but most of it is pretty firmly based in obvious metal riffing, even if keys or vocals are more accentuated.

When you get away from that and into more harsh noise-type sounds or hardcore or hard rock or something, that's when it isn't metal. I suppose if you asked me to specify more, I would classify metal riffs as being typically aggressive and moving the song along in a fluid way, with little breaking up the guitars. There are other genres that do that, but metal typically focuses on a complex riff-writing style with a lot of melody and grandiosity and atmosphere, rather than being used solely as a blunt instrument all the time.

But all that's secondary to my simpler explanation from before, which applies to most metal I'd say - yeah it split off into different genres, but none of it is so different that they're not still under the umbrella of metal.

I think this site's opinions come into play sometimes - like with bands like Deep Purple or Rush. But I'd argue the reason those bands were included is because they have enough metallic songs to be counted. Others might disagree. That's where the debate comes in - but not something so large as "we just can't actively say what metal is at all."

Heavy metal *is* a lot like bugs:

• You'll have folks who consider any (terrestrial) arthropod a bug, following common non-scientific use of the term; (aka "well if it's called metal by the general public, let's include it");
• But then you'll have the people who'll say "yeah but really only insects are bugs and not all terrestrial arthropods are insects" (aka "well there's some stuff that people throw under the metal umbrella that blatantly doesn't fit");
• And then come the entomologists who say "well sure in common use of English, every terrestrial arthropod or at least every insect is a bug but from a taxonomic point of view, only the insects that fit the criteria of the order Hemiptera are actual bugs. Just because plenty of the vernacular names of non-Hemipterans include "bug" doesn't make them actual bugs any more than it makes a ladybird a bird. If it doesn't have the Hemipteran mouthpiece which defines the order, it's not a Hemipteran and thus not a real bug." (aka "just because people call it metal (whether the genre or a specific band) doesn't make it so. If it doesn't have metal riffs, it's not metal.");
• And then you'll have other entomologists who will say "well yeah *most* scientists call all Hemiptera "true bugs", but the *real* "true bugs" are just those that belong to suborder Heteroptera, though the rest of the Hemipterans are closer to being true bugs than the rest of what folks call bugs" (you get the picture, I'm sure)

This isn't a tutorial, but at least provides a few examples of both "metal" riffs and "rock" riffs.

Can't get more classic metal with a rapper than this:






















And more serious answers to yours question:




Those above are quite ancient, so some contemporary stuff:

Everyone has made some pretty good points in this thread.

I'll try to take a shot at it with my limited understanding and knowledge, especially of music theory.

The riffs and riffing style to the best of my knowledge after listening to various genres (basic examples):
- Repeated almost as to set a theme, drive, bones, tension, flow, etc. of the song
-------4-5-------4-5-----------6-9-------------6-9--
0-0-0-----0-0-0-----0-1-1-5-----4--0-1-1-5------4

or some slower doomy stuff like (note rings out until next note is played):
1-----6-----4-----1-----6-----4-----

or stuff like this seen in power metal:
000000001111111122222222000000001111111122222222 (LOL)

or maybe some basic riff with power chords
---------5----------7----------5-----------7-
---------3----------5----------3-----------5-
0-0-0-0---0-0-0-0---0-0-0-0---0-0-0-0---

and sometimes there might be some random notes in between the repeated riffs, mini-riffs in a huge riff, riffing mixed in a solo, riffs spanning entire songs, bridges, etc., but there is still some sort of recognizable repetition (even if it it sometimes more difficult to catch in a lot of technical stuff). Some songs (or albums!) have only one or two riffs playing the entire time while others have dozens in one song like in the more speedy and technical stuff.

- Most of the time, I've observed that the riffs employed would include three or more notes (which would include the chug, gallop, etc.), but I guess this is debatable like most of my points.

- There are less broken riffs (like I believe someone else said) & shift of notes which tend to be discernible (perhaps due to the attack of the notes/chords?) and/or give a certain melody. Although attack might be a bit harder to catch in a lot of death and black metal when there is dissonance, tremolo picking, finger sweeping or in faster bands with fast riffs, the notes still tend to be discernible OR understood to be present and played in a certain fasion when there is a discernible melody. The playing in general can have a sort of impact, flow, tension, etc. I think a lot of the flow is what relates metal to classical a bit as well as flamenco, bluegrass, surf rock and probably a few other genres (playing a lot of metal clean can sound a bit like these genres). In general, its like a constantly moving and interconnected flow of notes. For slower stuff, the notes are obviously present and interconnected to form a huge spanning melody or theme.

- Some sort of distortion (whether its OD, fuzz, digital distortion, etc.) tends to help with the attack, hence its huge utilization. Also gives the riff somewhat of a presence (important).

There's probably a few other things in regards to just the riffing style and I'm sure there are others that can better explain. I don't expect for any of this to NOT be scrutinized either.

Outside of riffing itself, theres also the whole fact of how much of a song, album or entire discography should classify a thing as metal. Some expect 100% metal, others 90%, 80% and for some, 10, 20 or 30% of an album is metal enough (and I honestly think those are the ranges in which a casual listener and/or one not too familiar with metal will consider something to be "metal".

My .02 cents.

Interesting stuff in this thread. I don't have much to add other than I will say that I think its a bit unfair to classify bands like Korn and Disturbed right alongside with Slipknot under the "nu-metal" label. At the very least I think Slipknot is a fence riding band and I think of them as metal, for the most part. But again, it's subjective. I've just never felt right lumping Slipknot next to other bands from that era because they are night and day from say, Limp Bizkit, Coal Chamber, or Deftones.

tbh, to me, Disturbed always sounded closer to Pantera than to Slipknot or Korn, and since Korn and Slipknot don't sound much alike as well, kinda feels like the nu-metal label is the trash can for whatever doesn't sound metal enough, there's quite a range of different stuff in there

I also have real trouble classifying whatever Limp Bizkit used to do as nu-metal even, to me it sounded nothing more than a mix of hip hop, rock and hardcore, which is nowhere close to what the average nu-metal band sounds like

another 2 connotations i have real trouble with is avant-garde and post-metal, there's a bunch of bands that have this labels and yet are still counted as metal, while others fall outside the spectrum, not easy to tell at which point of experimentation does it become too much

All this shit about "metal riffs" goes flying out the window when you consider something like War Metal is considered a legitimate metal sub genre. And spare the "you must be new" bullshit.