Mohs Scale of Rock and Metal Hardness

If you're looking for the scale that ranks the hardness of actual rocks and metals, The Other Wiki has you covered. This one is about music.

Basically, a scale for ranking the "hardness" of music, "hardness" being the quality that separates rock from pop, Hard Rock from soft rock, Heavy Metal from Hard Rock, Death Metal from classic metal, noise from Industrial, and so on and so on.

Unfortunately, it's kind of a difficult concept to pin down, but trying as hard as possible:
 * More guitar distortion is the easiest measure of this. This is also the defining factor that separates metal from rock: guitars in metal sound metallic due to the amount of distortion. It's a bit difficult to classify those rare offshoots from rock that don't use guitars.
 * Similarly, the production quality can play a role. Generally, albums with a raw, unrefined sound lend themselves to sounding hard, and tend to fall towards that end of the scale. Some genres such as Grindcore take this to extremes and deliberately aim for a difficult listening experience as part of their aesthetic. However, as with all of these rules, exceptions can be found, and some of the very hardest bands can have an extremely polished, technical sound, where hardness is distinguishable mainly by other factors.
 * Louder and faster are good, but not definitive measures for this. Generally slow, quiet songs are softer than loud, fast songs, but there are definitely exceptions, though as a rule most hard songs are either loud or fast if they're not both. Funeral Doom and Drone Metal, for example, are both extremely slow but make up for this with extreme loudness, while other extreme genres break up loud sections of songs with quiet sections that nevertheless maintain speeds much greater than most pop music. Additionally, there's an important difference between "loud" and "hard", as a consequence of the Loudness War and variable production techniques - a lot of hard rock and good old fashioned heavy metal has gotten louder over time as re-released albums tend to be remastered with increased loudness, but this does not make them harder, while a death metal cover of a classic metal or rock song probably would be harder.
 * Length of the solo(s) is also a decent measure. Soft songs tend to have no guitar solo, up high in the metal hardnesses often the entire song builds up to the solo. (Of course, there are even more exceptions to this than to the loud and fast rule)
 * How Dark and Edgy the lyrics are, sometimes taking Refuge in Audacity. This is really only tangentially related to how hard the song actually is, but it's really the best measure if you can't figure out exactly how much distortion is on the guitar. A song titled "She Loves You" is going to be a lot softer than a song titled "Blunt Force Castration". Of course, many examples at the Lyrical Dissonance page exist to subvert this phenomenon. See the sister trope, Mohs Scale of Lyrical Hardness, for details.
 * Certain instrumental techniques are more commonly found in heavier rock or metal than in softer varieties: double-bass drumming (where the drummer uses two bass drums, or two bass pedals) is practically ubiquitous in extreme metal, but rarely heard in rock. Similarly, many metal guitarists make heavy use of techniques such as palm muting, tremolo picking and tapping, which tend to be used sparingly, if at all, in rock.
 * A sometimes-useful measure is how conventional the rhythms and melodies are. Most rock, pop, blues, dance music etc., is based around a simple 4/4 or 2/4 backbeat, (occasionally 6/8 or 3/4), and use either a blues scale or a diatonic scale. By contrast, prog-metal or experimental bands make heavy use of unusual rhythms and time-signatures, and extreme metal bands tend to ignore melody for the most part (with exceptions like Melodic Death or Black Metal, and sometimes Progressive Death Metal ). However, both unusual melodies and rhythms are very common in some forms of softer music, especially jazz: Dave Brubeck's "Take Five", for example, could easily fit into #1 on this scale, but is written in the very unusual 5/4 time signature with an unusual key signature.
 * As noted below, vocal style (singing, as opposed to shouting, screaming, or growling) is a good measure of hardness, not merely in the style used but in how frequently a particular style is used. It's not especially uncommon, for example, for modern alternative rock artists to use singing predominantly and screamed vocals on occasion, while more mid-range hard styles like metalcore may make extensive use of shouting, while deploying death growls infrequently to add a darker tone to some passages. If, on the other hand, screams or growls are used constantly, or as the main vocal style with softer, clean vocals used only to lighten some parts of a song, you're probably looking at at a substantially harder band.

Rough outline of the levels:
 * 1) As soft as rock gets. May be an otherwise 2 song without any guitar to distort, or a song which is generally slow and light.
 * 2) Soft rock. A lot of early rock is here; if you're not really sure if they're using an acoustic or an electric guitar, this is probably where you want to put it.
 * 3) Rock sans intensifier. A bit faster/louder/darker than 2, but still pretty soft. The heaviest soft rock and the softest hard rock can both be found here.
 * 4) Relatively harder rock. This is about where you can start finding punk, as well; lighter than this and you can't usually muster the kind of anger you need for punk. This is pretty much as heavy as Rock n' Roll got.
 * 5) Hard rock that is definitely still rock. The love songs start thinning out here, but lyrics at this stage can be about just about anything. The very softest of alt-metal can also get this low, but it is very rare.
 * 6) Difficult to tell if it's rock or metal. This is pretty much as far as you can get on just an acoustic guitar. Most Glam Metal and softer Post-Grunge can be found here. This is where you'll also find softer Alternative Metal.
 * 7) Classic metal and most Power Metal. After this point the number of punk bands begins to decrease, with the remaining examples predominantly of the hardcore punk variety. The music is pretty fast and noisy at this point. The lyrics start to become darker, though vocalists still use clean, melodic styles most of the time. The heavier sides of Glam and post-grunge can be found here as well as most Nu Metal. Viking and Folk metal starts showing up around here. The lightest Groove Metal can be found here.
 * 8) Most Thrash Metal, and heavier forms of Power Metal along with some classic metal. Lyrics are usually very dark at this point. Vocal style is usually a snarl, but clean singing is also common. Occasionally growls and screams will be employed. The harder side of hardcore punk is here, and Metalcore (fusion of thrash metal and hardcore punk) starts to predominate. Whether purists want to hear it or not, the lighter and more atmospheric side of Black Metal also starts here. You'll also find yet more viking/folk metal populating this region. Most Groove Metal is here. This is pretty much as heavy as you can get with radio airplay (with a few exceptions).
 * 9) Lighter Death Metal (especially Melodic Death Metal) or harder Thrash Metal. You'll also find a lot of the less abrasive 'true' Black Metal here. Here is about where you start to get singers growling or screaming for most of the song (This is also probably the highest level that can be attained with only clean singing). Lyrics may be very violent or just generally extremely dark. This is the last zone where you are likely to find hardcore punk that doesn't have a substantial metal or noise infusion. This is also about where Metalcore starts to transition to Deathcore (which also begins around this level). Most viking/folk metal that has a significant infusion of Black Metal or Death Metal falls here. A lot of the heavier side of Groove Metal is found here.
 * 10) Most Death Metal and Black Metal. Lyrics start to get positively disturbing and/or gorny and the singer will always be growling or screaming. The hardest variants of Thrash Metal, Melodic Death Metal, and viking/folk metal can hit this point, but that is quite uncommon. At this point hardcore bands become indistinguishable from metal to anyone who's not a loyal fan of both genres. Grindcore starts here. While it is possible for a metalcore band to get this high, it's very rare. Groove Metal at this level usually has a lot of Death Metal influence.
 * 11) Up to Eleven: Anal Cunt is here, along with the harder side of Grindcore especially the subgenres of pornogrind, noisegrind and goregrind. The most extreme Death Metal (a good portion of the brutal death metal and slam death metal subgenres end up up here) and Black Metal also lies here. The very heaviest mathcore (technical, chaotic hardcore) can also reach this level. Growling or screaming will start sounding almost inhuman, and often pitch-shifting or other computer-aided effects are used to drive the vocal range beyond what could normally be sustained during singing[[hottip:*:(astoundingly though, not always). Significant elements of this class are [[True Art Is Incomprehensible|experimental]] in nature, although Stealth Parodists commonly make their way up here as well.

Notes:
 * A very well exemplified illustration of different levels of metal heads and the most stereotyped opinions.
 * Lower hardnesses are not bad. Remember, The Beatles come in at 2-3, and 10 (or above) can be unlistenable. Likewise, higher hardnesses are not bad. Remember that even though it may sound like impenetrable noise to you, that doesn't mean in principle it isn't enjoyable, nor that it doesn't contain real musical sophistication and talent.
 * As time goes on, those metal bands at the top of this chart go to increasingly insane lengths to top one another or themselves, which causes the chart to compress itself to accommodate the new hardness. So a 6 now could be a 4 or 5 ten years from now.
 * Level 11 exists in general for the placement of any music that is definitely harder or crazier than what is common at 10. While this may seem obvious, the important distinction to make is that anything at 11 should still exist within an easily identifiable genre, such that a familiar listener should easily be able to place it as Grindcore, Death Metal, Black Metal, or whatever genre it may draw from. What stops it from being a 10 is merely that it takes an additional step beyond what is popular in any given year within the 10 range of albums, either in terms of an increasingly raw, chaotic sound or in terms of sheer speed, or progressive technical brutality. In fact, one of the key and most helpful descriptors of level 11 is the word "crazier", which is often the way it sounds to most listeners until the style gains a bit of popularity and moves down into 10.
 * Corollarily, anything beyond 11 starts to become Noise. Noise is a category for unsortable experimental music that is extreme in ways other than being "heavy" in a traditional fashion. Anything by Merzbow, and most other Noise artists belongs here. There really are no identifiable guitars, basses, drums, or even vocals, and the music tends to become overwhelmed with extended techniques including computer sound manipulation. Here artists (and listeners) are mainly interested in exploring the limits of what can be interpreted musically, whereas at 11 listeners and musicians are merely interested in pushing the boundaries of existing genres. However, the genre-fucking mutability of things like Level 11 Grindcore tends to create ambiguity in this respect.
 * In general, a band will have songs that are higher or lower on the scale than their usual level, hence why websites like Wikipedia put some bands and/or albums as both rock and metal. (Compare "Tourette's" and "Polly", both by Nirvana.) It's easier to just judge each song by itself. You also have bands that change their style, often becoming heavier, softer, or becoming a genre that's much harder to classify altogether.
 * The reason some of the metal Fan Dumb hates power metal is that it is a rare exception to the above rule that metal bands tend to get harder over time.
 * Interestingly enough, a live performance, remix, or reissue of a song can actually be a different level than the original studio version, especially if an extended solo(s) or guest musicians are involved. Volume compression (which is frequent on recent remasters of old material) may arguably contribute to different hardnesses between releases as well.
 * Christian Metal is usually as heavy as its mainstream counterpart; however, in most cases, Christian metal lyrics aren't as dark as secular metal. So, a song could be a 10 or 11 in musical heaviness, while the lyrics could be about the power of God's love for the world. Obviously not all Christian metal songs are like this, but it's a common part of the genre, and the point still stands. As mentioned above, the lyrics are only indicators and don't play a direct part in the song's hardness, so you don't need to place Christian metal songs at a lower hardness just because of the lyrics.
 * Similarly, many of the more progressive, technical artists who reside at the hard end of the scale (Augury, Death, Neuraxis, and Cephalic Carnage, to name a few) generally write lyrics which, while certainly quite cynical, and darker than most at the soft end of the scale, aren't especially graphic or disturbing. Their lyrics are often highly philosophical, reflective, introspective, or merely less visceral as opposed to the outright Gorn written by many of the other bands residing at the top of the scale. Such exceptions also apply to bands such as Napalm Death and The Agonist which write politically or socially conscious lyrics.
 * Sometimes, songs with symphonic elements can be at a lower level of hardness than they would be without the symphonic elements. It depends on how the elements are implemented in the song, however; some more extreme artists use symphonic elements to provide a contrast between blast beats and the like, and manage to be just as heavy as other conventional death/black metal bands. Similarly folk elements work much the same way. Sorting these songs out on a case-by-case basis is the best solution.
 * Melodic tendencies can play a part in the song's hardness. Similar to the above note regarding symphonic elements, melody can decrease the hardness of a song, but it depends on how it's used, and as such the songs will be handled on a case-by-case basis.
 * Your Mileage May Vary: What's extreme to you may sound accessible, even catchy to the next person, so level assignments are highly subjective. For example, many tropers place metal ballads in level 6. On the other hand, seeing as how metal ballads typically interconnect softer acoustic/piano passages with harder electric guitar/percussion driven passages (that may otherwise reach into 8 to 9 range), one could just as easily assign them to level 7 or 8, depending on how far one felt certain passages removed the music from a level one felt was enjoyable. This is especially true in the case of progressive death metal, where extended symphonic, jazzy, proggish, or folkish passages are commonly interlaced with full-on level 10 blasting. Consider The Lair of Purity by Augury and The Lotus Eater by Opeth by way of example: are these songs brutalising extreme metal, or are they lighter and gentler progressive metal?
 * Even within each level, there are varying degrees of heaviness. For example, Voices of the Dead is definitely a heavier and more aggressive song than Nightmare. But "Nightmare," thanks in no small part to lines like "Your fucking NIGHTMARE!" and brief moments of Metalcore screaming, is ultimately heavy enough to be an 8. While "Voices Of The Dead" is ultimately too melodic for a 9.

Level 1

 * Imagine (John Lennon)
 * Here Comes the Sun (The Beatles)
 * Turn Turn Turn (The Byrds)
 * Imperfect (Stone Sour)
 * Living in the Sunlight (Tiny Tim)
 * Good Riddance (Green Day)
 * I Want Love (Elton John)
 * My Heart Will Go On (Celine Dion)
 * Happy Together (The Turtles)
 * Sky Chord (Tsuji Shion)
 * Richland Woman Blues (Mississippi John Hurt)
 * The Silent Man (Dream Theater)
 * Samson (Regina Spektor)
 * That's the Way (Led Zeppelin)
 * No Surprises (Radiohead)
 * Song to the Siren (This Mortal Coil)
 * Home At Last (Steely Dan)
 * Thick As A Brick Edit 1 (Jethro Tull)
 * Lipan Conjuring (Tool)
 * Darkness (Disturbed)
 * Patterns In The Ivy (Opeth)
 * You Look So Fine (Garbage)
 * Such Small Hands (La Dispute)
 * Untitled (How Could This Happen to Me?) (Simple Plan)
 * Just The Way You Are (Billy Joel)
 * Dance Macabre (Decapitated)
 * Inception (Spawn Of Possession)

Level 2

 * Nowhere Man (The Beatles)
 * Never Gonna Give You Up (Rick Astley)
 * Travel is Dangerous (Mogwai)
 * Although it's an 11 live
 * No Rain (Blind Melon)
 * Optimistic (Radiohead)
 * Hurt (Nine Inch Nails)
 * Yellow (Coldplay)
 * Character Zero (Phish)
 * Wish You Were Here (Pink Floyd)
 * Something In The Way (Nirvana)
 * Torn (Natalie Imbruglia)
 * Breathless (The Corrs)
 * Under The Bridge (Red Hot Chili Peppers)
 * Everything (Lifehouse)
 * Ain't Afraid to Die (Dir en grey)
 * Nutshell (Alice in Chains)
 * Crucify (Tori Amos)
 * Going to a Town (Rufus Wainwright)
 * Mushaboom (Feist)
 * All My Love (Led Zeppelin)
 * Vermillion Part 2. (Slipknot)
 * Nothing Else Matters (Metallica)
 * Planet Caravan (Pantera)
 * Two-Headed Boy (Neutral Milk Hotel)
 * Mr Blue Sky (Electric Light Orchestra)
 * Through Glass (Stone Sour)
 * Amanda (Boston)
 * The Sound of Silence (Simon and Garfunkel)
 * Babe (Styx)
 * So Far Away (Avenged Sevenfold)
 * Sanctuary (Utada Hikaru)
 * Dance Dance Dance (Lykke Li)
 * I'm Just A Singer (In A Rock And Roll Band) (The Moody Blues)
 * Sleep (Copeland)
 * Can't Fight This Feeling (REO Speedwagon)
 * It's Still Rock And Roll To Me (Billy Joel)
 * Remember Everything (Five Finger Death Punch)

Level 3

 * Pinball Wizard (The Who)
 * Everywhere (Michelle Branch)
 * Beat It(Michael Jackson)
 * Just Like Heaven (The Cure)
 * Drive (Incubus)
 * Sympathy for the Devil (The Rolling Stones)
 * All Apologies (Nirvana)
 * Starship Trooper (Yes)
 * Birdhouse in Your Soul (They Might Be Giants)
 * Black Hole Sun (Soundgarden)
 * B.I.T.C.H. (Meredith Brooks)
 * Stirb nicht vor Mir (Rammstein}
 * Combine Harvester (The Wurzels)
 * My Love is a Stapler (Afterschool Tea Time; K-On!)
 * Harvest (Opeth)
 * Time (Pink Floyd)
 * Trains (Porcupine Tree)
 * In The Fade (Queens of the Stone Age)
 * Slippin Away (Hypocrisy)
 * Snuff (Slipknot)
 * Stairway to Heaven (Led Zeppelin)
 * Yellow Ledbetter (Pearl Jam)
 * Action & Action (The Get Up Kids)
 * Space Oddity (David Bowie)
 * Since U Been Gone (Kelly Clarkson)
 * Hotel California (The Eagles)
 * Turn To Stone (Electric Light Orchestra)
 * Ears Ring (Rainer Maria)
 * Sorry Again (Velocity Girl)
 * Some Natures Catch No Plagues (Saetia)
 * More Than A Feeling (Boston)
 * Only Happy When It Rains (Garbage)
 * Subdivisions (Rush)
 * One Lonely Visitor (Chevelle)
 * Rock Me (Great White)
 * Rock Around the Clock Tonight (Bill Haley and the Comets)
 * Do It Again (Steely Dan)
 * Angel (Luscious Jackson)
 * Closing Time (Semisonic)
 * Keep on Loving You (REO Speedwagon)
 * Hold the Line (Toto)
 * Suicide Note, Part 1 (Pantera)

Level 4

 * Satisfaction (The Rolling Stones)
 * Hound Dog (Elvis Presley)
 * You May Be Right (Billy Joel)
 * Vertigo (U 2)
 * Everlong (Foo Fighters)
 * Supermassive Black Hole (Muse)
 * Rock the Cashbah (The Clash)
 * Alive (Pearl Jam)
 * How You Remind Me (Nickelback)
 * Let's Fighting Love (DVDA)
 * Trippin' On A Hole In A Paper Heart (Stone Temple Pilots)
 * Sk8er Boi (Avril Lavinge)
 * Push it to the Limit (Paul Engemann)
 * My Guitar Wants to Kill Your Mama (Frank Zappa)
 * Another One Bites The Dust (Queen)
 * We Know Where You Sleep (The Paper Chase)
 * Dani California (Red Hot Chili Peppers)
 * What I've Done (Linkin Park)
 * Escapism (An Cafe)
 * This is Love (PJ Harvey)
 * Extraordinary (Liz Phair)
 * Declare Independence (Bjork)
 * Over the Hills and Far Away (Led Zeppelin)
 * Cut Your Hair (Pavement)
 * Suite Madame Blue (Styx)
 * Tiger Feet (Mud)
 * Say It Ain't So (Weezer)
 * Mr Brightside (The Killers)
 * Chelsea Dagger (The Fratellis)
 * Say You'll Haunt Me (Stone Sour)
 * Peace of Mind (Boston)
 * Last Chance (Shooting Star)
 * Shameful Metaphors (Chevelle)
 * Miss America (Saving Abel)
 * Auctioned (Dark Tranquillity)
 * Swanheart (Nightwish)
 * Midnight Moonlight (The Firm)- not a youtube video
 * Ready, Willing, and Able (Petra)
 * Get Thru This (Art of Dying)
 * Roundabout (Yes)
 * Venus in Furs (Velvet Underground)
 * Don't Fear The Reaper (Blue Oyster Cult)
 * Under Your Skin (Luscious Jackson)
 * Paint it, Black (The Rolling Stones)
 * American Woman (The Guess Who)
 * Pretty Fly for a White Guy (The Offspring)
 * The House Is Rockin' (Stevie Ray Vaughan)
 * De Sangre Hermosa (Ill Nino)
 * The Unforgiven (Metallica)
 * Skeleton Song (Sevendust)
 * Écailles De Lune Pt. 1 (Alcest)
 * The Lost Art Of Keeping A Secret (Queens of the Stone Age)

Level 5

 * Now I'm Here (Queen)
 * Smoke On The Water (Deep Purple)
 * Back in Black (ACDC)
 * American Idiot (Green Day)
 * Cat Scratch Fever (Ted Nugent)
 * Society (Pennywise)
 * Seven Nation Army (The White Stripes)
 * Higher (Creed)
 * Gay Bar (Electric Six)
 * Pretend We're Dead (L 7)
 * Purple Haze (Jimi Hendrix)
 * The Kids Aren't Alright (The Offspring)
 * Immigrant Song (Led Zeppelin)
 * Rock of Ages (Def Leppard)
 * Anarchy in the UK (Sex Pistols)
 * Victory (Bad Religion)
 * Same Old Song And Dance (Aerosmith)
 * One Last Goodbye (Anathema)
 * 100% (Sonic Youth)
 * Princess of The Night (Saxon)
 * Masturbating Smile (Kuroyume)
 * Won't Get Fooled Again (The Who)
 * La Villa Strangiato (Rush)
 * In the Dark (The Birthday Massacre)
 * Talk To You Later (The Tubes)
 * Here's Your Future (The Thermals)
 * Hyper Enough (Superchunk)
 * For Want Of (Rites of Spring)
 * Because It's Midnite (Limozeen)
 * Ziggy Stardust (David Bowie)
 * Cherry Bomb (The Runaways)
 * Run Run Away (Slade)
 * Hell Raiser (The Sweet)
 * The Family Disease (Oceana)
 * Bodhisattva (Steely Dan)
 * Locomotive Breath (Jethro Tull)
 * Konya Wa Hurricane (Bubblegum Crisis)
 * Teenagers (My Chemical Romance)
 * Help Save The Youth of America From Exploding (Less Than Jake)
 * Opheliac (Emilie Autumn)
 * Ignorance (Paramore)
 * Working For The Weekend (Loverboy)
 * Rockin' The Suburbs (Ben Folds)
 * Satellite (Rise Against)
 * Tonight (Seether)
 * Jerry Was A Race Car Driver (Primus)
 * Black Lodge (Anthrax)
 * Snail (Do As Infinity)
 * Supervixen (Garbage)
 * DESTINY -The Lovers- (Versailles) - Depending on your view, either the guitar solos keep this from being a 4 or the ballad sections keep this from being a 6.
 * Only Shallow (My Bloody Valentine) - MBV's entire Signature Style is that they essentially wrote pop songs that were brute-forced to this level of hardness by Kevin Shields' wall of guitar noise.

Level 6

 * 2112: Overture/Temples of Syrinx (Rush)
 * The Hitman (Queen)
 * Welcome to the Jungle (Guns N' Roses)
 * Fade To Black (Metallica)
 * Rooster (Alice in Chains)
 * Arena of Pleasure (W.A.S.P.)
 * Killing Me, Killing You (Sentenced)
 * Vermillion Part 1. (Slipknot)
 * No Way (Korn)
 * Plug In Baby (Muse)
 * Demon Cleaner (Kyuss)
 * Coma White (Marilyn Manson)
 * Detroit Rock City (KISS)
 * Taxicab Messiah (Kidneythieves)
 * My Girlfriend's Girlfriend (Type O Negative)
 * Be Quiet and Drive (Deftones)
 * Hell's Kitchen (Dream Theater)
 * Smells Like Teen Spirit (Nirvana)
 * Bullet With Butterfly Wings (The Smashing Pumpkins)
 * Getchoo (Weezer)
 * Stargazer (Rainbow)
 * Addicted To Chaos (Megadeth)
 * Stone the Crow (Down)
 * A National Acrobat (Black Sabbath)
 * Eagle Fly Free (Helloween)
 * No One Knows (Queens of the Stone Age)
 * On Fire (Van Halen)
 * Go (Pearl Jam)
 * Nobody's Fault But Mine (Led Zeppelin)
 * Cemetery Gates (Pantera)
 * Thunderstruck (ACDC)
 * Bang Yer Head (Portraits of Past)
 * My Cat (Jack Off Jill)
 * Stockholm Syndrome (Muse)
 * Super Buu's Theme Bruce Faulconer
 * Fell In Love with a Girl (The White Stripes)
 * Mutter (Rammstein)
 * Consequences / The Melancholy (Iced Earth)
 * The End (The Doors)
 * God Save The Queen (Sex Pistols)
 * I Wanna Be A Drug Sniffing Dog (Lard)
 * Cold December (Presence)
 * Pardon Me (Incubus)
 * Die Trying (Art of Dying)
 * Not Again (Staind)
 * Helter Skelter (The Beatles)
 * No, Thank You!! (K-On!)
 * Wicked Garden (Stone Temple Pilots)
 * Rapture (Hurt)
 * Misery Business (Paramore)
 * To Holmgard and Beyond (Turisas)
 * Self Esteem (The Offspring)
 * Vow (Garbage)
 * All I Ask For (Ill Nino)
 * Crazy Train (Ozzy Osbourne)
 * Deadwing (Porcupine Tree)
 * Face of Melinda (Opeth)
 * Blackest Eyes (Porcupine Tree) - One could argue that the HEAVY main riff brings the song up to a 7 (hence its inclusion on the "7" list), so Your Mileage May Vary.
 * Pieces (Hoobastank)
 * Dawn Patrol (Megadeth)
 * Curse of Rose (Kaya feat. Hizaki) - This song is what happens when a Synth Pop performer asks a Power Metal guitarist to compose a song for him.

Level 7

 * Numb (Linkin Park)
 * Jurahevin Kuninkaat (Hevisaurus)
 * Through the Fire and Flames (Dragonforce)
 * Number of the Beast (Iron Maiden)
 * Omeano Tettuini Kugimo Ute (JAM Project)
 * Warfare (Jag Panzer)
 * Eat My Diarrhea (GG Allin)
 * Unleashed (Epica)
 * Sleep Now In the Fire (Rage Against the Machine)
 * Wish (Nine Inch Nails)
 * Bodies (Drowning Pool)
 * Exciter (Judas Priest)
 * New Born (Muse)
 * Energize Me (After Forever)
 * Set the World on Fire (Symphony X)
 * The Czar (Mastodon)
 * Dead Star (Muse)
 * Last Before The Storm (Gamma Ray)
 * Zero / Fuck You(The Smashing Pumpkins)
 * The Curse Of Feanor (Blind Guardian)
 * Highlander (Lost Horizon)
 * Parabola (Tool)
 * Whole Lotta Love (Led Zeppelin)
 * I Against I (Bad Brains)link
 * Travel in Stygian / Stand Alone (Iced Earth)
 * Born Too Late (Saint Vitus)
 * Venus Blue (Acid Bath)
 * Pull Me Under (Dream Theater)
 * Guardian (Fates Warning)
 * I Don't Believe in Love (Queensryche)
 * Our Solemn Hour (Within Temptation)
 * The End of Heartache (Killswitch Engage)
 * Somebody Someone (Korn)
 * Millenium (Stratovarius)
 * Pump the Brakes (Refused)
 * Leaving All Behind (Cellador)
 * Lorelei (Theatre of Tragedy)
 * Leaves (The Gathering)
 * Nemo (Nightwish)
 * Gaia (Tiamat)
 * Holy Tears (Isis)
 * Hearts on Fire (HammerFall)
 * Wild One (Dio)
 * Sakkyun Light (Sekken-ya; Touhou Project Fan Vid)
 * No More Sorrow (Linkin Park)
 * It's About Time (Van Halen)
 * Welcome Home (Coheed and Cambria)
 * Psalm 9 (Trouble)
 * Mirror of Sorrow (Solitude Aeturnus)
 * Art Of Life (X Japan)
 * Cause Disarray (Galneryus)
 * Renegade (Hed PE)
 * Green Machine (Kyuss)
 * This is the New Shit (Marilyn Manson)
 * Wearing and Tearing (Led Zeppelin)
 * Sick, Sick, Sick (Queens of the Stone Age)
 * Breakfast of Champions (Comadre)
 * Hole in the Sky (Axel Rudi Pell)
 * Open Your Heart (Crush 40)
 * Prepare For Oblivion (Universe At War soundtrack)
 * Riding the Storm (Running Wild)
 * Paper Moshay (Antioch Arrow)
 * Hold Me Down (Hardline)
 * Then Again, Maybe You Were Right (La Dispute)
 * Armi Beter (Plonk Moist)
 * One Little Victory (Rush)
 * Memento Mori (Kamelot)
 * Blow Me Away (Breaking Benjamin)
 * Hammerhead (The Offspring)
 * Prince Charming (Metallica)
 * Moving Very Slowly (Taranchula)
 * Pain for Pleasure (Sum 41)
 * Down With the Sickness (Disturbed)
 * Assistant to the Regional Manager (The Devil Wears Prada)
 * Replace Me (Family Force 5)
 * Life After Death and Taxes (Relient K)
 * Treason (Kutless)
 * I Am (All of Me) (Crush 40)
 * Ultra (KMFDM)
 * Criminal (Attack Attack!)
 * Ride (Presence)
 * California Uber Alles (Dead Kennedys)
 * Yours (Toby Mac)
 * Carry On, Wayward Son (Kansas Cover) (The Showdown)
 * Ace of Spades (Motörhead)
 * Blackest Eyes (Porcupine Tree)
 * Meaningless (Mnemic)
 * This Love (Pantera) - A good example of a metal ballad whose "heavy parts" are heavy enough to bring the song above a 6
 * One Armed Scissors (At the Drive-In)
 * Resuscitation of a Dead Man (Thursday)
 * Kokou no Sousei - (Yousei Teikoku)
 * What Doesn't Die (Anthrax)
 * Family System (Chevelle)
 * Unholy Confessions (Avenged Sevenfold)
 * Écailles De Lune Pt. 2 (Alcest)
 * Not The American Average (Asking Alexandria)
 * How Can I Live (Ill Nino)
 * Bread of Shame (Creed) (bet you didn't expect to see them here)
 * Blood Of Heroes (Megadeth)
 * Angry Chair (Alice in Chains)
 * The Set Up (Zebra Head)
 * TRUE (Exist Trace)
 * Metalingus (Alter Bridge)

Level 8

 * Endless, Nameless (Nirvana) [The quiet parts keep it from earning a 9 or 10]
 * The Donkey-Headed Adversary of Humanity Opens the Discussion (Sleepytime Gorilla Museum)
 * Battery (Metallica)
 * Head Crusher (Megadeth)
 * Given Up (Linkin Park)
 * Among the Living (Anthrax)
 * Striker (Annihilator)
 * Firestorm (Earth Crisis)
 * Trollhammaren (Finntroll)
 * Clouds over California (Devildriver)
 * Prison Song (System of a Down)
 * Mein Teil (Rammstein)
 * One Step Closer (Linkin Park) The soft verses keep it from getting a 9.
 * The Flood (The Haunted)
 * Starchild (Wintersun)
 * The Saints (Helloween)
 * Not Unlike the Waves (Agalloch)
 * Guilty of Being White (Minor Threat)
 * Take the Night Off (Sick of it All)
 * Dragula (Rob Zombie)
 * Nerve (Soilwork)
 * Evenfall (Tristania)
 * At the Gallows End (Candlemass)
 * Forests in Fire and Gold (Drudkh)
 * Depth Charge (Devin Townsend)
 * Land of the Dead (Summoning)
 * Leave Me Here (Cult of Luna)
 * Nightmare (Venom)
 * King of a Stellar War (Rotting Christ)
 * Beat it Upright (Korn)
 * Empire Falls (Primordial)
 * Imperium (Machine Head)
 * Burning Inside (Ministry)
 * Souls of Black (Testament)
 * Rumors of War (High on Fire)
 * E1M1: At Doom's Gate (Robert Prince; Doom 3DO soundtrack)
 * Starfire Burning Upon the Ice Veiled Throne of Ultima Thule (Bal-Sagoth)
 * A Looking in View (Alice in Chains)
 * The Dark Eternal Night (Dream Theater)
 * Hammer of Damnation (Demoniac)
 * Epic Questions (Pagan's Mind)
 * The Devil Incarnate (Death Angel)
 * Dead (Norther)
 * Walk (Pantera)
 * Woodlawn (Ampere)
 * Destination - Blood! (Orchid)
 * Nightmare (Avenged Sevenfold)
 * God Hates Us (Avenged Sevenfold) - While (as of this writing) this is definitely the heaviest thing A7x has done in years, it's still ultimately too melodic and "catchy" to be a 9.
 * Pisleen Tendril
 * Who Wants A Dose Of The Clap? (The Locust)
 * Chelsea Smile (Bring Me the Horizon)
 * Forgive and Forget (Miss May I)
 * AC-130 (Attack Attack!)
 * Tales of a Scorched Earth (The Smashing Pumpkins)
 * Don't (Dinosaur Jr)
 * Not So Posi After All (Punch)
 * Young God (Swans)
 * Nikopol (Gurren Lagann soundtrack)
 * Nothijngrad (Novembre)
 * Dust Devils And Cosmic Storms (myGRAIN)
 * Chester (Disarmonia Mundi)
 * Misery's Crown (Dark Tranquillity)
 * Hybrid Cult (Scar Symmetry)
 * Sugarcoat (Breaking Benjamin)
 * A Plot to Bomb the Panhandle (A Day to Remember)
 * Farewell to Shady Glade (Of Mice and Men)
 * Seven (Symphony X)
 * Birdo (Horse The Band)
 * Acidhead (Tourniquet)
 * Into The Storm (Blind Guardian)
 * Remnants/Asylum (Disturbed)
 * Live at the Sandopolis (Braincells)
 * Flesh (KMFDM)
 * Carol of the Bells ( August Burns Red)
 * Breath Of the Swamp (The Showdown)
 * Snowdrifts (Dark Lunacy)
 * Ignite (Living Sacrifice)
 * Burning Times (Iced Earth)
 * Desperate Times, Desperate Measures (Underoath)
 * Dirge for November (Opeth) - The softer acoustic bits are what keep it below a 9.
 * Moon of My Nights (Kalmah)
 * The Last Stand of Frej (Amon Amarth)
 * Behind The Crooked Cross (Slayer)
 * Telecastic Fake Show (Ling Tosite Sigure)
 * There's Going to Be a War! (Nonpoint)
 * Through the Eyes of the Devil (Mercenary)
 * Welcome Home (King Diamond)
 * The Red Carpet Day (Versailles)
 * Rusty Nails (God Dethroned)
 * Moonshield (In Flames) - If not for its heavy use of acoustic guitars, this would definitely be a 9.
 * Voices of the Dead (Kreator)
 * Blondevil (Onesidezero)
 * We Are Godzilla, You are Japan (Lostprophets)
 * Pain Killer (Judas Priest)
 * China Town (Van Halen) - The pure speed and agressivness keepts it from being a 7.

Level 9

 * Angel of Death (Slayer)
 * Beneath The Remains (Sepultura)
 * Spirit Crusher (Death)
 * Heartwork (Carcass)
 * Jotun (In Flames)
 * Fight Fire with Fire (Metallica)
 * Facing Failure (Funeral)
 * Slaughter of the Soul (At the Gates)
 * The Face of My Innocence (Arsis)
 * Enemy Within (Arch Enemy)
 * Now you've Got Something to Die For (Lamb of God)
 * Your True Enemy (Nachtmystium)
 * Cake and Sodomy (Marilyn Manson)
 * Slaughtered (Pantera)
 * Zombie Autopilot (Unearth)
 * New Abortion (Slipknot)
 * Bodies on Bodies (Vio-Lence)
 * Slave (Amebix)
 * Footprints (Warning)
 * Dopethrone (Electric Wizard)
 * Death Metal (Possessed)
 * Twilight of the Thunder God (Amon Amarth)
 * Master Killer (Merauder)
 * Insect Whore (Dwarves)
 * Our Saviour (Paradise Lost)
 * Chant for Eschaton 2000 (Behemoth)
 * Pleasure to Kill (Kreator)
 * Piece of Time (Atheist)
 * Veil of Maya (Cynic)
 * The Air that I Breathe (All That Remains)
 * Feed the Gods (White Zombie)
 * This Darkened Heart Steeped In the Abyssal Void (He Who Bathes In The Black Sun) [The soft guitar tone prevents this from scoring an 11]
 * Apocalyptic Havoc (Goatwhore)
 * Fire in the Sky (Hypocrisy)
 * One by One (Immortal)
 * Existence is Punishment (Crowbar)
 * Take as Needed for Pain (Eyehategod)
 * Body Parts (Sodom)
 * March of the Fire Ants (Mastodon)
 * I Will Be Heard (Hatebreed)
 * Circle of the Tyrants (Celtic Frost)
 * Darkness Descends (Dark Angel))
 * Boss Theme: Face to Face (Tom Mauritzon; Iji soundtrack)
 * Burned At The Stake (Morbid Saint)
 * Punish My Heaven (Dark Tranquillity)
 * The Serpentine Offering (Dimmu Borgir)
 * Deeper Down (My Dying Bride)
 * Drawn to Black (Insomnium)
 * Wreath (Opeth)
 * Axiom (Akercocke)
 * Skyless (Augury)
 * Where Dead Angels Lie (Dissection)
 * Through Her Silvery Body (Swallow the Sun)
 * Embrace (Angelcorpse)
 * Twilight (Edge of Sanity)
 * Satan's Hammer (Destroyer 666)
 * Serpent Angel (Moonspell)
 * Towards The Crown Of Nights (Covenant)
 * Serenity In Fire (Kataklysm)
 * I Used To Hate Cell Phones But Now I Hate Car Accidents (Norma Jean)
 * You're Better Off Dead (Children of Bodom)
 * Capital Distracts And Imprisons (Bucket Full of Teeth)
 * White Silhouette (Omniscient Spine)
 * This Is Exile (Whitechapel)
 * Monkeys Disarm Their Kremlings (Neko Frog)
 * Miasma (The Black Dahlia Murder)
 * My Tourniquet (Soul Embraced)
 * Columbian Necktie (Big Black)
 * Gattai Nante Kuso Kurae (Gurren Lagann soundtrack)
 * Conservatory Resonance (Novembre)
 * Otherworld (Nobuo Uematsu, Final Fantasy X soundtrack)
 * Funeral In Carpathia (Cradle of Filth)
 * Bland Street Bloom (Sik Th)
 * Pitch Black Progress (Scar Symmetry)
 * Motherland (Dark Lunacy)
 * Snüffel (Equilibrium)
 * Relentless (Strapping Young Lad)
 * Heavy Lies the Crown (The Showdown)
 * Marianas Trench (August Burns Red)
 * Perfect Night For a Hanging (Tourniquet)
 * Anodyne Sea (As I Lay Dying)
 * The World Is a Thorn (Demon Hunter)
 * All Hope Is Gone (Slipknot)
 * Dr. Shavargo Pt 2 (Attack Attack!) (This is significantly heavier than the album version)
 * Mannequin (Cradle of Filth)
 * Vagrant Idol (Demiricous)
 * Nihilism (God Dethroned)
 * A Lesson Once Learned (Man Must Die)
 * Web of Fire (Mortification)
 * From Your Grave (The Absence)
 * Victorious Dawn Rising (Centinex)
 * Arise From Decay (Dew-Scented)
 * Romulus (Ex Deo)
 * Act of War (Lich King)
 * Bleed the Meek (Paths Of Possession)
 * The Angels Venom (Monstrosity)
 * Killing You, Killing Me (Ill Nino)
 * Under and Over It (Five Finger Death Punch)
 * Eyes of a Criminal (Chimaira)
 * Evil in You (Kalmah)
 * D.O.A. (The Haunted)
 * Faceless One (Hate Eternal)
 * doxa incarnate (Mutyumu)
 * Stay Here (Swans)
 * Buried Dreams (Carcass)
 * Legions Of The Dead (Testament)
 * Discharge (Anthrax)
 * Extreme Hatred (Hypnosia)
 * Powershifter (Fear Factory)
 * Burnt Tongues (Your Demise)
 * In My Own Greed (Spawn Of Possession)
 * People = Shit (Slipknot)
 * Xeroxed (Mushroomhead)
 * JUDEA (Exist Trace)

Level 10

 * Rape Song (Strapping Young Lad)
 * Becoming God (Augury)
 * Hammer Smashed Face (Cannibal Corpse)
 * Junky (The Amenta)
 * Deathcrush (Mayhem)
 * Dunkelheit (Burzum)
 * Endless Cycle of Violence (Cephalic Carnage)
 * New Millenium Cyanide Christ (Meshuggah)
 * Death With Dishonor (Sigh)
 * Blooddawn (Marduk)
 * Panasonic Youth (The Dillinger Escape Plan)
 * Happy Valentine's Day (Psyopus)
 * Papyrus Containing the Spell to Preserve its Possessor Against Attacks From He Who is in the Water (Nile)
 * Raping A Slave (Swans)
 * Knee Deep (Job for a Cowboy)
 * Silence Calls the Storm (Quo Vadis)
 * Earthly Love (Gorguts)
 * Godeye (Kalmah)
 * Spheres of Madness (Decapitated)
 * Slowly We Rot (Obituary)
 * Ocean Gateways (Obscura)
 * Stabwound (Necrophagist)
 * Skin Her Alive (Dismember)
 * Charred Remains (Autopsy)
 * Báthory Erzsébet (Sunn O)
 * Darkness Prevails (Neuraxis)
 * Epoch of the Gods (Psycroptic)
 * Out of the Body (Pestilence)
 * Bleed The Fifth (Divine Heresy)
 * One Shot, One Kill (Dying Fetus)
 * Synthetically Revived (Suffocation)
 * No Guts No Glory (Bolt Thrower)
 * No Heroes (Converge)
 * Slutstation Babylon (Skitsystem)
 * Sworn (Emperor)
 * Coldly Calculated Design (The Faceless)
 * Whispering Breeze (Ildjarn)
 * Cold Hate, Warm Blood (Cryptopsy)
 * Subconscious Terror (Benediction)
 * Killing Art (Hypocrisy)
 * For the Masses (Gorefest)
 * Suck My Blood (Beherit)
 * Dark Transmission (Vader)
 * Revelation of Doom (Gorgoroth)
 * Towering Flesh (Pig Destroyer)
 * The Descent (Today is the Day)
 * Demoralizer (The Red Chord)
 * Backbone (Gojira)
 * Rewards of Cruelty (Severed Savior)
 * Homage for Satan (Deicide)
 * Everlasting (Thergothon)
 * Dagon Undone: The Reckoning (The Showdown)
 * Arsonry (Cobalt)
 * The Ancient Ones (Morbid Angel)
 * Mouth of Empty Praise (Bloodbath)
 * Your Prophetic Throne of Ivory (diSEMBOWELMENT)
 * Soda In the Water Cup (Atilla)
 * Enjoy the Violence (Massacra)
 * Slaves Shall Serve (Behemoth)
 * Ritual (Blasphemy)
 * Plague Rages (Napalm Death)
 * Of Wolf and Fear (Ulver)
 * Norge (Thorr's Hammer)
 * The Awakener (Kataklysm)
 * Reciprocal (Origin)
 * In Die Nacht (Dornenreich)
 * King Of All Kings (Hate Eternal)
 * Stabat Mater Dolorosa (Anorexia Nervosa)
 * Big Smile (Hatred Surge)
 * Incinerated (Broken Hope)
 * Parasignosis (Mitochondrion)
 * Yippie-Kay-Yay Mother!@#$%^ (The Tony Danza Tapdance Extravaganza)
 * Dechristianize (Vital Remains)
 * My Spine! My Spine! My Spine! (Combat Wounded Veteran)
 * Bite Me (Weird Al Yankovic) ... bet you didn't expect to see him here.
 * Ode (Drunkdriver)
 * Lurch (The Dillinger Escape Plan)
 * Tastes Like Kevin Bacon (iwrestledabearonce)
 * Into Darkness (Soul Embraced)
 * Carving a Giant (Gorgoroth)
 * My Nemesis (Impending Doom)
 * Eye of the Tiger (Ten Masked Men)
 * War Ensemble (As I Lay Dying)
 * The Violation (Fleshgod Apocalypse) (where the symphonic elements help the heaviness)
 * Portrait of Souls (Annotations Of An Autopsy)
 * Tides of Vengeance (Iniquity)
 * The Black Uncharted (Keep Of Kalessin)
 * Scrolls of the Megilloth (Mortification)
 * The Lean Black Cruisers (Panzerchrist)
 * Lash By Lash (Spawn Of Possession)
 * Waters of Space (Deeds Of Flesh)
 * Dreamdecipher (Miseration)
 * Imperial Doom (Monstrosity)
 * Distorted (Devolved)
 * Agitated Screams of Maggots (Diren Grey)
 * Climactic Degradation (The Black Dahlia Murder)
 * Comatose (Chimaira)
 * Self-Pity Human (In Thy Dreams) Here because of the sheer aggression of the music, in contrast to most of the Melodic Death Metal out there.
 * Terminal Liberation (Mors Principium Est) Similar to the case above.
 * Dynamic (Sybreed) Despite the clean vocals at the end, the song's ultra aggressive pace still keeps it at this level.
 * Medical Deviance (Aborted)
 * The Lair of the White Worm (God Dethroned)
 * Suicide The End (Detrimental)
 * Inflicted (Obliteration)
 * Powerful Sickness (Fetal Decay)
 * Crushed (Brutality)
 * Suicide Note, Part 2 (Pantera) - Bet you didn't expect to see Pantera get this high on the list.

Level 11

 * Skinned (Mortician)
 * You're Pregnant, So I Kicked You in the Stomach (Anal Cunt)
 * Sadistic Abductive (Brain Drill)
 * Ulcerated Offal (Last Days of Humanity)
 * Mr. Game and Watch is a Mass Murderer (Hello Kitty Suicide Club)
 * Festerday (Carcass)
 * Bloated Slabs (Enmity)
 * Pandemonic Hyperblast (Anaal Nathrakh)
 * Ylem (Wormed)
 * Degredation Paradox (Human Mincer)
 * Anal Destruction (Abörted Hitler Cöck)
 * No One Wins (The Berzerker)
 * Teeth of Emulation (Disfiguring The Goddess)
 * The Endmills (Portal)
 * Hyungga is a tangled story (Pyha)
 * Built to Grind (Agoraphobic Nosebleed)
 * Razorized Ball Gag (Gutteral Secrete)
 * Jaundice of Hookworm (Disgorge (Mexico))
 * Valley of the Impaled (Internal Suffering)
 * Consumed by Repugnance (Defeated Sanity)
 * Self Disembowelment (Devourment)
 * Rectum Grinder (Intestinal Disgorge)
 * On the Supreme Legions(Against Failing Humanity) (Mindly Rotten)
 * Toilet Cleaning (Corpse Penis Eaten By Rectum)
 * Puddle of Sewage Rot (Demonic Dismemberment)
 * Right Angel Triangle (Brazen Bull)
 * Testicles Dance (Jig Ai)
 * Raped By Elephants (Torsofuck)
 * Colon Commando (Fuck... I'm Dead)
 * Asuka (Gridlink)
 * Substantial Guilt VS. The Irony of Enjoying (Ion Dissonance)
 * In Reverence Of (Impending Doom)
 * Doe Deer (Crystal Castles)
 * Casket Krusher (Exhumed)
 * Your Blood Is Mine (Severe Torture)
 * Stitched Oral Asphyxia (Gorgasm)
 * In For The Kill (Inhume)
 * Tomorrow (Panzerchrist)
 * Thru Our Scars (Fleshgod Apocalypse)