Of the seven modes a guitarist can pull out of the white keys, the Phrygian is the darkest one a riff can stand on for four minutes without the floor giving way, and heavy metal found it by ear, one fret at a time, long before anybody in a denim jacket had a name for it or cared to learn one.
The courtier who, in the story Cicero tells in the Tusculan Disputations, envied Dionysius II, tyrant of Syracuse, for his throne until he was invited to sit on it and looked up to find a sword hanging over his head by a single horsehair, point down, was Damocles. The flat second of the Phrygian mode hangs over its home note in exactly that way, one semitone of air between the steel and the scalp, and every time the riff drops from the F to the open low E the hair snaps and the blade comes down through the open string.
That drop is the whole mode. The rest of the notes are the natural minor that the music already lived in, and the place of both among the power chord, the tritone and the gallop is laid out in the related chapter. The half step is another matter: which way it pulls, what chord it drags in behind it, and what waits one step darker still.
Phrygian mode: metal's mirror of the major scale
Count the steps. A major scale climbs whole, whole, half, whole, whole, whole, half, and its last step is the semitone from the leading note up to the tonic, the pull that has brought Western music home for three centuries. The Phrygian, E to E on the white keys, climbs half, whole, whole, whole, half, whole, whole, which is the major pattern read exactly backwards. It is the major scale held up to a mirror.
Walk the Phrygian downhill from the top, E, D, C, B, A, G, F, E, and the steps come out whole, whole, half, whole, whole, whole, half, the major pattern note for note. Any guitarist can prove it on a single string in under a minute.
The mirror reverses the gravity. In major the home note is reached by a semitone from below, a lift upward that sounds like arrival; in Phrygian it is reached by a semitone from above, a fall, and a fall onto the floor of the key sounds like something being put down that will not get up again. Classical harmony built its cadences on the rising pull. Heavy metal, by common consent, built its riffs on the falling one.
A love song, a Passion and a Phrygian tune
The Nuremberg organist who wrote one of the great Phrygian melodies of the European tradition, in 1601, as a love song about a heart thrown into confusion by a girl, was Hans Leo Hassler. Within twelve years the tune had been taken into the Lutheran church, printed in a 1613 Görlitz hymnal under a dying man's prayer, and in 1656 Paul Gerhardt set to it the Passion hymn "O Haupt voll Blut und Wunden", the head covered in blood and wounds. A love song had become a hymn of the Passion without changing a single note of its melody.
The Leipzig cantor who harmonised that Phrygian tune five times over in his St Matthew Passion, first heard on Good Friday, 11 April 1727, was Johann Sebastian Bach, and each of the five settings stands under its own harmony, never repeating the last one note for note. The mode was carrying grief two centuries before an amplifier existed. The lineage is older than anybody's riff.
The flat second chord and the missing third
Build a chord on the Phrygian's second note and it is major: F major in E Phrygian, the chord that classical theory calls the Neapolitan when it turns up in a minor key, a borrowed brightness that makes the return home feel darker by contrast. On a distorted guitar it shrinks to the power chord F5, one fret above the open E5, and the whole of the Phrygian's menace reduces to a single hand hammering one fret up and one fret down.
That is also why so much of the music is Phrygian by a single note and nothing more. A power chord has no third, so a riff that sits on E5, A5 and D5 could be Aeolian, Dorian or Phrygian, and nothing in it decides. The second decides. A riff that never touches the note above the root has no mode at all beyond a vague minor darkness; a riff that leans on the F declares itself at once, whether its author ever opened a theory book or not.
Played together rather than one after the other, E and F are the harshest pair in the octave. Their frequencies sit so close that they beat against each other, a roughness the ear takes in as a grinding surface rather than as two notes, and distortion multiplies the by-products until the pair turns to gravel. Heavy metal mostly kept the two notes apart, one after the other, and let the fall do the work.
A riff that leans on the F declares itself at once, whether its author ever opened a theory book or not.
The singer who wrote the title track of Iron Maiden's Powerslave, released by EMI on 3 September 1984, and built its verse on a riff in A Phrygian that keeps pressing on the note one fret above home before it turns toward the brighter, harmonic minor colour of its final bar, was Bruce Dickinson. The Egyptian setting did the rest of the work in the imagination. The half step did it in the ear.
The band that made the half step a trademark a few years later was Metallica. The main riff of "Wherever I May Roam", from the untitled album of August 1991, is by common description E Phrygian, palm muted on the low string with the F kept close at hand, and the thrash side of that story belongs to its own silo. What matters here is how ordinary the move had become. Two frets, one direction, no apology.
| Mode | On the white keys | Against the major scale | Home chord |
|---|---|---|---|
| Lydian | F to F | Raised fourth | Major |
| Ionian (major) | C to C | None | Major |
| Mixolydian | G to G | Flat seventh | Major |
| Dorian | D to D | Flat third and seventh | Minor |
| Aeolian (natural minor) | A to A | Flat third, sixth and seventh | Minor |
| Phrygian | E to E | Flat second, third, sixth and seventh | Minor |
| Locrian | B to B | Flat second, third, fifth, sixth and seventh | Diminished |
One step darker: the Locrian
Lower one more note, the fifth, and the Phrygian becomes the Locrian, the last mode on the ladder and the only one whose home chord is diminished. The tritone that the old theory books placed under anathema now sits inside the tonic triad itself, between the root and its fifth, so the chord that is supposed to mean home cannot sit still for a single bar.
The tower in the Campo dei Miracoli at Pisa began to lean in the 1170s, when its third storey was going up on soft clay that swallowed the footings on the south side, and the masons who resumed the work a century later built the upper storeys taller on the sinking side, bending the column back against its own lean. The finished tower is not straight at all. It is curved. A Locrian riff stands the same way. Its home chord leans, so the writer bends every phrase back toward a steadier note, usually by stepping around the flat fifth over the root, and the riff stands because of the bend, not in spite of it.
The scientist who, in a story first told by his pupil Vincenzo Viviani, dropped two balls of different weight from the gallery of that tower to see which landed first was Galileo Galilei, and nobody has ever proved he did it. The Locrian has a reputation of the same kind in guitar lessons: talked about far more than it is played. Metallica's "Sad But True" is the example guitar teachers reach for, and even there the Locrian colour sits on top of power chords that keep a perfect fifth the true mode does not allow, so the harmony leans Locrian without ever quite committing to it. Beyond that it lives mostly in the solos and the chromatic runs of thrash and death metal, which have silos of their own.
Which leaves the Phrygian as the dark bastion that actually holds. It is the last mode with a minor chord to stand on, the first with a semitone pressing down onto the root, and the forebear of nearly every riff that shuttles between the open low string and the first fret. Why the whole music settled at the dark end of that ladder in the first place, rather than in its bright middle, is the question behind why metal loves the minor key.
The answer on the fretboard is shorter. One fret. It has been enough for half a century.
