In 1863 a retired Prussian infantry major published a short book in Berlin on secret writing and the art of reading it, and inside it he broke a cipher that had held for three centuries. The system carried the name of Blaise de Vigenère, although Giovan Battista Bellaso had described it first in 1553, and it worked by pencilling one short keyword over the dispatch again and again, every letter of the message shifted by the letter written above it, so that six letters of key could colour ten thousand words of text.
Its flaw was the repeat. The officer who found it, by measuring the distance between the groups of letters that came round twice and prising the whole dispatch apart along those seams, was Friedrich Kasiski.
Metal riffs are that cipher built backwards. The key is short, two to six notes and a rhythm, it is repeated under the whole song, and the repetition is not a weakness to be hidden but the entire mechanism, because the listener is meant to crack the code by the second bar and feel it in the neck by the third. Nothing is concealed. That is the design.
The raw materials, the bare fifth, the tritone, the Phrygian half step and the slackened string, belong to heavy metal theory. Assembly is a separate trade, learned by ear in rehearsal rooms long before anybody wrote it down, and it runs in five operations: cut a cell, repeat it, answer it, leave holes in it, and decide who plays it.
Metal riffs start from a cell
A cell is the smallest group of notes that still sounds like itself: a handful of pitches, a rhythm, and usually a shape the fretting hand can hold without travelling far along the neck. It lives in the rhythm more than in the pitches. Change two notes and a player still recognises it; move the accents and it becomes somebody else's riff.
Cells travel, and they never ask permission. Released as a single in June 1970 and taken to number two in Britain, "Black Night" runs on a figure its makers admitted lifting from the arrangement of "Summertime" on a 1962 Ricky Nelson record, and the quintet that took a pop singer's bass line, bolted a distorted Hammond organ onto it and drove it up the singles chart in an onslaught of volume answered to Deep Purple. The cell survived the trip. Everything around it changed.
That is the first lesson of the trade. A cell is not judged by where it came from, only by whether it can bear being played thirty times in a row, and very few can.
The hand shapes the cell before the ear does. Most heavy riffs are written inside a span of four or five frets near the bottom of the neck, where an open string can ring between the fretted notes and the picking hand can batter the lowest string without the player looking down, which is why so many of them sit in E or A, the notes of the two lowest open strings. A cell written for the hand survives the tempo going up. A cell written on paper usually breaks in the first rehearsal.
Three times the same, then an answer
Most riffs are cut into four units, four bars or four half bars, and the commonest plan states the cell, states it again, states it a third time and changes the fourth unit so that the figure turns round and heads back to its start. Players call that change the turnaround. The first three statements load the ear; the fourth pays it, and the whole riff comes round again with the tension reset to zero.
The count matters more than the notes, and the plainest proof came out of a rehearsal room. The guitarist who brought the riff of "Enter Sandman" to the band in 1990, worked up at home after an evening with Soundgarden's Louder Than Love, was Kirk Hammett, and the drummer who took it apart and had him repeat the opening figure four times before the rest of the riff was allowed in was Lars Ulrich.
Nothing new was added. Only the count changed, and the riff that came out of that edit opened the self-titled album Metallica released through Elektra in August 1991, with the opening figure hammered in before the answer is allowed to arrive. Repetition is not padding. It is the tension the turnaround spends.
There is a second way to answer. Instead of changing the last unit, a band can lift the whole cell, carrying it up a fourth or a fifth for the second half of the riff the way the blues carried its first chord up to the fourth, so that the figure comes back unchanged in shape and higher in pitch, and the reply lands with the full weight of the original behind it. The shape stays; the ground moves.
The first three statements load the ear; the fourth pays it.
The rest is part of the riff
A golfer at the top of the backswing holds the club still for a fraction of a second, the whole body wound against itself, and it is that frozen instant, not the swing, that decides how hard the head comes down, tears a divot out of the turf and sends the ball two hundred yards up the fairway. A rest in a riff does the same work. The silence loads the next note.
The most famous riff in rock is mostly holes. On "Smoke on the Water", from Machine Head in March 1972, the figure runs G, B flat, C and a gap; G, B flat, D flat, C and a gap; the first phrase again and a gap; and finally B flat falling to G, and the gaps are as fixed as the notes. The third phrase repeats the first, the fourth answers everything, and the silences between them hold the whole salvo in place.
Accents do the rest of the work. A riff whose heavy note lands on the first beat of the bar marches; a riff that strikes it half a beat early, ahead of the bar line, pushes, and the listener's body leans forward to meet it. Most of the difference between a figure that drags and one that drives is decided there, before a single pitch is chosen.
| Operation | What it does | Hear it on |
|---|---|---|
| Cut a cell | A few notes and a rhythm the hand can hold in one position | Deep Purple, "Black Night" (1970) |
| Repeat it | Loads the ear before anything changes | Metallica, "Enter Sandman" (1991) |
| Answer it | A changed last unit turns the figure back to its start | Deep Purple, "Smoke on the Water" (1972) |
| Leave holes | Rests fixed as firmly as the notes | Deep Purple, "Smoke on the Water" (1972) |
| Double it | Bass and guitar on one line | Cream, "Sunshine of Your Love" (1967) |
Who plays the riff
The last decision is who carries the figure. In the blues the bass walked under the guitar on a line of its own, and the heavy bands made it take the same line, in unison or an octave down, so that a figure played on six strings arrives with the tonnage of both instruments behind it. The lineage of that habit runs back through the rehearsal rooms of the late sixties, and it began, more often than guitarists admit, on the bass.
The bassist who wrote the riff of "Sunshine of Your Love", reportedly after watching Jimi Hendrix at the Saville Theatre in London in January 1967, was Jack Bruce, and on Cream's Disraeli Gears that November bass and guitar play it together, note for note, the drums working round the figure rather than hammering through it. The riff carried the song. Nobody needed a chord sequence.
The creed of the style has held ever since: whoever writes the riff, everybody plays it.
Cut, repeat, answer, rest, double: five operations, and a teenager with a borrowed amplifier can run all of them in an afternoon. Running them so that a full hall hears the fourth bar coming and roars before it lands is the work of a career, and the cells nobody has managed to improve on are gathered in the greatest metal riffs.
