So geographers, in Afric maps, / With savage pictures fill their gaps, / And o'er unhabitable downs / Place elephants for want of towns.Jonathan Swift, On Poetry: A Rhapsody
Every heavy metal genres chart is drawn the way an architect draws a floor plan, each style a clean rectangle and each border a hard line of black ink, and every one of them goes wrong in the same place. The people who lived in the house spent forty years taking bolster chisels to the party walls, knocking doorways through the brickwork wherever two rooms wanted to share a riff.
The boxes are the easy part. The crossings are the map.
Most of the charts that fans pass around are trees, one trunk and a spray of branches, and a tree is the right shape for descent and the wrong shape for almost everything else. The quartet at the root of nearly every one of those trees, sitting in the first box before a single line is drawn, is Black Sabbath, and the rest hangs from it. The lines along which the parent style broke apart are set out in how the branches divide. A chart earns its keep somewhere else, on the borders, where two branches that were supposed to have parted company for good turn out to share a stage.
What a heavy metal genres chart actually draws
Three things sit on any chart worth printing, whether or not its maker meant them to. Position along the page is usually time, the older styles at the top or on the left. Distance between two boxes is a claim about kinship. The lines are a claim about who learned from whom, and they are the part most often wrong.
A line on a chart points one way. The records never did. Thrash took speed from the British wave and then handed it straight back to the heavy metal bands of the late eighties, doom took its riffs from Black Sabbath and lent its tempo to the gothic bands of the nineties, and the chroniclers who drew the arrows had to choose a direction for traffic that ran both ways at once. Every arrowhead is a small lie. Most of them are useful lies.
The famous charts differ mostly in how they tell those lies. Sam Dunn's genealogy for his 2005 film fanned out from a trunk of founders, while Musicmap, the online atlas of popular music built by the Belgian architect Kwinten Crauwels, sets metal as a cluster of its own, with hybrid genres reaching out toward industrial, gothic and electronic music. Neither is wrong. Each is a different projection of the same country.
The border towns, where two styles meet

The Houston band that named its 1987 album after the border itself was D.R.I., and Crossover, released by Metal Blade, set hardcore punk shouting and short songs on top of thrash riffs until neither side could claim the record alone. Two years earlier the New York side project Stormtroopers of Death had pressed the same mix onto Speak English or Die for Megaforce, songs that came off the machine like newsprint from a rotary press run past its rated speed, sheets tearing at the folds and still somehow legible. Crossover was not a branch. It was a border crossing.

The Halifax quintet that slowed death metal to the pace of a funeral and kept the growl was Paradise Lost, and Lost Paradise, released by Peaceville in 1990, sits on the border between death and doom so exactly that neither branch of the tree can draw it without the other. Within a year the same band had moved one border further along. On a tree that move needs three lines. On a map it needs one.
The Brooklyn quartet that pushed the doom riff into gothic rock and watched Bloody Kisses go platinum was Type O Negative. Released by Roadrunner in 1993, the record went gold in 1995 and platinum in 2000, the label's first record to do either, and "Black No. 1" stretches its riff like a cane of molten glass pulled the length of a workshop floor, sagging and thinning as it goes until it snaps under its own weight, while Peter Steele's bass voice sits underneath like the lowest pedal pipe of a cathedral organ holding its note under the choir. No chart has ever found a single box for it.
Every arrowhead is a small lie. Most of them are useful lies.
More border towns, and the roads out of the city
The Palm Desert quartet that ran Sabbath riffs through amplifiers powered off a generator in the open desert was Kyuss, and Blues for the Red Sun, released by Dali in 1992, puts "Green Machine" on the border between doom and the older psychedelic rock of the seventies, a place stoner metal has occupied ever since. Its fans rarely call it heavy metal. Its riffs rarely ask.
Other borders fell the same way. The West Midlands band that welded hardcore punk to extreme metal on Scum, released by Earache in 1987, and left grindcore standing in the rubble was Napalm Death. Ministry bolted thrash guitars to drum machines on The Land of Rape and Honey in 1988, and Bathory slowed its black metal into Norse epic on Blood Fire Death the same year. In Trieste, Rhapsody put an orchestra behind power metal on Legendary Tales in 1997.
| Hybrid | The border it sits on | The record that marks it | Year |
|---|---|---|---|
| Crossover thrash | Thrash and hardcore punk | D.R.I., Crossover | 1987 |
| Grindcore | Hardcore punk and extreme metal | Napalm Death, Scum | 1987 |
| Industrial metal | Thrash and industrial | Ministry, The Land of Rape and Honey | 1988 |
| Viking metal | Black metal and epic heavy metal | Bathory, Blood Fire Death | 1988 |
| Death-doom | Death metal and doom | Paradise Lost, Lost Paradise | 1990 |
| Stoner metal | Doom and psychedelic rock | Kyuss, Blues for the Red Sun | 1992 |
| Gothic metal | Doom and gothic rock | Type O Negative, Bloody Kisses | 1993 |
| Nu metal | Groove metal and hip hop | Korn, Korn | 1994 |
| Symphonic power metal | Power metal and the orchestra | Rhapsody, Legendary Tales | 1997 |
| Metalcore | Melodic death metal and hardcore punk | Killswitch Engage, Alive or Just Breathing | 2002 |
The last rows are where most charts stop drawing, and the argument starts. Korn in 1994 and Killswitch Engage in 2002 both sit several borders away from Paranoid, and whether a chart gives them a box or leaves them off the page says more about the man holding the pen than about the records. The schism over nu metal is thirty years old. Nobody has won it.
Reading the chart without being fooled by it
The first rule is to trust the record over the label. A box marked speed metal or gothic metal is a summary of fifty bands, and any one of them can sit at the far edge of it; the record in the hand decides which border it leans toward. The second is to count crossings rather than generations. A band that crossed two borders on one album tells more about the shape of the map than a band that spent thirty years inside one.
The third is to watch for the elephants, the boxes drawn where a chart maker needed something to fill the space. The Umeå band whose palm-muted, off-kilter chords gave a whole box its name is Meshuggah, and djent, the word for that sound, began as guitarist Fredrik Thordendal's own drunken onomatopoeia for his tone, picked up by a fan and passed on as a genre name the band never chose for itself. A box with a name is not always a style with a history.
The last is to remember that the old styles keep being rebuilt. The traditional heavy metal revival of the 2000s plays the rules of 1982, which means a chart drawn strictly by date puts its newest bands next to its oldest, and a chart drawn by sound has to loop its own arrows back on themselves. The bloodlines, generation by generation, belong to the heavy metal family tree, whose pedigree runs one way only.
A chart is a bridgehead, not a territory. It gets a listener across to the far bank and tells nothing about the country behind it, and the only honest use of one is to pick a border town, buy the record that marks it and hear for once what two styles sound like when they stop pretending to be strangers. Then go back and redraw the chart.