A pop song is a chord sequence that goes round and round while the tune on top of it changes. A heavy metal song is a set of riffs, each one a separate piece of machinery with its own shape and its own job, and heavy metal song structure comes down to two decisions only: the order in which the riffs arrive, and which of them is allowed to come back.
An orb-weaving spider builds to that kind of order every night, slinging the frame lines between two stems first, running the dry radii out from the hub like the spokes of a cartwheel, and only at the very end laying the sticky spiral round that scaffolding, the one part of the structure made to stop a moth dead in flight and pin it there while the fangs go in. Everything before the spiral carries weight. Only the spiral catches.
The riffs that open a heavy metal song are the frame and the spokes, load bearing and dry, and the chorus is the part built to catch. The Aston guitarist who packed four and five separate riffs into a single song, at a time when a pop writer would have hung the whole thing on one progression, was Tony Iommi, and the habit went into the foundations of the style alongside the volume and the tuning. The parts those riffs are cut from were counted out in the earlier chapter. The order they go in is a separate craft.
Heavy metal song structure is counted in riffs
The pop trade names its sections after what the singer does: verse, pre-chorus, chorus, bridge. A heavy metal band names them after what the guitars play, and in a rehearsal room the parts are mostly called by the riff, the slow one, the fast one, the one before the solo, which is why the form of almost any song in the style can be drawn on the back of a beer mat as a row of letters. A is the main riff. B is whatever comes next.
Released by Vertigo in September 1970 on Paranoid, "Iron Man" draws the whole map in under six minutes: a slow opening of bent notes, the main riff with bass and guitar locked on the same line, verses sung on top of it, a lift into a faster riff for the solo, the main riff again, and a closing section that speeds up once more and plays the song out. The quartet that drew it went by the name Black Sabbath. Four riffs, and no chord chart anywhere.
The riff that opens a song is rarely finished with it. In most heavy metal songs the intro riff comes back as the hinge between a chorus and the next verse, so that by the second pass a listener hears it as home ground, and a section that never returns registers as a sortie out of the song rather than part of its body. Structure, at bottom, is bookkeeping: which riff has been heard, how often, and how long since.
Verse, chorus and the lift between them
Between verse and chorus many songs set a short section of two or four bars whose only job is to raise the pressure. The harmony climbs, the drummer moves off the hi-hat onto the ride cymbal or the crash, and the guitars stop chugging and hold their chords, letting each one hang across the bar while the snare starts to fill the gaps the riff has left. The pre-chorus is a promise. The chorus has to keep it.
The chorus itself comes in two designs. In the first it rides the verse riff and the change is carried by the voice alone, the title thrown out on the strong beat; in the second the band switches to a new riff, usually one built on longer chords that ring rather than chug, so that the sound opens out as the singer arrives. The second design costs a riff. It is nearly always worth it.
Loud and quiet can carry the form on their own. Released by Elektra on ...And Justice for All, a record dated variously to 25 August and to early September 1988, "One" sets its verses on clean, picked guitars and lets the distortion in only for the choruses, running that alternation round twice before something else takes over, and the band that stretched the device to seven and a half minutes answered to Metallica. The forebear is older. The Birmingham five that had set clean verses against a heavy chorus a decade earlier, on "Beyond the Realms of Death" in 1978, was Judas Priest.
The middle belongs to the guitars
After the second chorus the singer usually steps back, and what follows works like the games on the sand of the Colosseum, where attendants raked the arena floor clean between bouts and sent out a man with a net and a trident against a man with a sword and a closed helmet, the net flung to tangle the blade, the trident driven through the shield, in a space cleared of everything except the fight. The middle of a heavy metal song is that raked floor.
The band drops to a riff simple enough to fight on and sends the soloist out onto it, and three moves change the ground under him: a new key, a new tempo, or a riff heard nowhere else in the song and never heard again. "Iron Man" takes the second, lifting the tempo for its solo and dropping back to the main riff when the guitar is done. The listener feels the floor shift. Nobody needs to name the key.
A chorus is not the loudest part of a song. It is the bar the song was written to reach, and a band that cannot point to that bar has written a medley.
Julien Vasseur, KaosMetal
The most famous middle of the eighties stops the song altogether. Halfway through the title track of Master of Puppets, released by Elektra in March 1986, the thrash riffs fall silent for a clean interlude of picked chords and a slow melodic lead, harmonised in two guitars, before the heavy riffs crash back in under a faster solo and the verse returns intact. The rhythm guitarist who wrote and played that slow melody was James Hetfield.
The pre-chorus is a promise. The chorus has to keep it.
| Section | What the band plays | What it is for |
|---|---|---|
| Intro | The main riff alone, or a slow build before it | Names the song before a word is sung |
| Verse | A riff with room left in it for the voice | Carries the words |
| Pre-chorus | Two or four bars of held chords and rising harmony | Raises the pressure |
| Chorus | The verse riff with the title on top, or a new riff of ringing chords | The part built to be remembered |
| Middle | A new riff, a new key or a new tempo, with a solo over it | Hands the song to the guitars |
| Coda | The intro riff again, or material never heard before | Decides whether the song goes home |
Endings: going home, or leaving
There are two ways out. The cyclic ending plays the intro riff one last time and stops dead on the final chord, four players hitting it together and choking the strings in the same instant, so that the listener walks away with the first thing heard still ringing. The through-composed ending never goes back. It treats the opening of the song as a place it has already left.
Written by James Hetfield after the band's equipment was stolen before a show in Boston in January 1984, "Fade to Black", on Ride the Lightning that July, spends its second half abandoning its first: the acoustic verses give way to heavier riffs, the voice returns once over new material, and the last minutes go to a long solo over a progression the song has not used before, closing the record on it. The guitarist who carries it out of the room is Kirk Hammett.
"One" makes the same departure four years later and makes it harder, trading the ballad for a double kick drum barrage, a riff fired in bursts like a stuttering machine and a tapping solo, and not one verse from the first half ever comes back. Neither ending is better than the other. The cyclic song is built for a crowd that wants to hear its own opening shouted back; the through-composed song is built for a listener who has agreed to be taken somewhere, and on any record a band makes, the choice between them is attested by the last thirty seconds.
Structure is the order of the riffs, and the order is only half of what a riff is made of. The other half is the string it is played on, and the simplest change to that string, one slackened a whole tone so that the lowest chord falls under a single finger, is set out under what is drop D tuning.
