Heavy metal

History and character

“Classic” heavy metal is the metal of Black Sabbath (1970) and, above all, of the late 1970s and the 1980s: Judas Priest (who codified the aesthetic: two guitars, a high-pitched singer, leather and studs), Motörhead, the New Wave of British Heavy Metal (Iron Maiden, Saxon, Diamond Head, Angel Witch, early Def Leppard), Dio and Rainbow, Ozzy Osbourne as a solo artist with Randy Rhoads, Scorpions, Accept, Mercyful Fate. In the United States: Riot, Manowar, early Queensrÿche.

The sound: galloping riffs and palm-muted riffs, two guitars in harmony (thirds and fifths, a legacy of Thin Lizzy and Wishbone Ash), fast melodic solos, a very present bass (Steve Harris), drums with double kick on the gallops, high, powerful vocals with vibrato (Rob Halford, Bruce Dickinson, Ronnie James Dio), and epic, historical, fantasy or rebellious lyrics. The sound is less compressed and less downtuned than modern metal: guitars in standard tuning or a half step down, Marshall amps with moderate gain, and plenty of room ambience.

Heavy metal is the foundation of power metal, thrash, speed metal, traditional doom and all the metal that followed; in the 2000s–2020s it enjoys an “NWOTHM” revival (New Wave of Traditional Heavy Metal: Enforcer, Night Demon, Visigoth, Ghost with a pop twist).

Scales and keys

Aeolian (natural minor)

• Formula: 1 2 b3 4 5 b6 b7 (W H W W H W W).
• Example in E: E F# G A B C D.
• Characteristic note: b6 (C) → major VI chord.
• Chords: i Em, ii° F#dim, III G, iv Am, v Bm, VI C, VII D.
• Use: galloping riffs, diatonic third harmonies between the two guitars (in Aeolian the thirds are major or minor depending on the scale degree), i–VI–VII choruses.
• Real example: Iron Maiden — The Trooper (E minor, third harmonies); Iron Maiden — Run to the Hills.

Harmonic minor

• Formula: 1 2 b3 4 5 b6 7 (steps in semitones 2-1-2-2-1-3-1). In E: E F# G A B C D#.
• Characteristic note: D# (leading tone) → major dominant B.
• Chords: i Em, III+ G+, iv Am, V B, VI C, vii° D#dim.
• Use: Randy Rhoads solos, V–i cadences in the choruses, diminished arpeggios.
• Real example: Ozzy Osbourne — Crazy Train (F# minor with harmonic colors in the solos; the riff is in F# Aeolian/pentatonic).

Phrygian and Phrygian dominant

• Phrygian: 1 b2 b3 4 5 b6 b7 (in E: E F G A B C D). Phrygian dominant: 1 b2 3 4 5 b6 b7 (in E: E F G# A B C D).
• Characteristic note: b2 (F) over the open string; in the dominant form also G#.
• Use: menacing riffs (Judas Priest, Mercyful Fate), “oriental” intros (Iron Maiden — Powerslave in E Phrygian dominant).

Dorian (1970s heavy)

• Formula: 1 2 b3 4 5 6 b7. In A: A B C D E F# G.
• Use: blues-heavy riffs (Black Sabbath, Deep Purple, Rainbow): major IV in a minor key.

Minor pentatonic and blues

• Formula: 1 b3 4 5 b7 / 1 b3 4 b5 5 b7. In E: E G A B D / E G A Bb B D.
• Use: more rock-oriented solos (Tony Iommi, Adrian Smith), Sabbath riffs (Iron Man: B D D E E G F# G F# G F# D D E E: B pentatonic/blues).

How to choose

• Epic gallop: Aeolian. Neoclassical solo or V–i cadence: harmonic minor. Oriental intro: Phrygian dominant. 1970s riff: pentatonic/blues and Dorian.
• Two-guitar harmonies: write the melody in Aeolian and harmonize a third above while staying in the scale (diatonic thirds), not in parallel major thirds.

Harmony

Function

Modal minor harmony with the gallop as the engine: i–VI–VII–i, the Andalusian descent (i–VII–VI–V), a tonic pedal with power chords moving above it. V–i cadences (from harmonic minor) in the epic choruses; VI–VII–i cadences in the endings.

Two-guitar harmonies

• Melodies in diatonic thirds (Iron Maiden, Judas Priest), sometimes in fifths or sixths; third harmonies give a “heroic” sound.

Pedal

• Riffs with the open E string repeated in a gallop and notes moving above it (E–E–E–G, E–E–E–A).

Harmonic rhythm

• One chord per bar in the choruses; changes every beat in the riffs.

Voicing

• Power chords with the octave, full chords with the third only in the clean parts (arpeggios), octaves in the melodic unisons.

Typical progressions

Rhythm and groove

4/4 with the gallop as its signature (an eighth note plus two sixteenth notes: “da-da-dum”), medium-fast tempos, a strong backbeat; heavy midtempo songs (Breaking the Law, Holy Diver) and fast songs with double kick. Variants: the reverse gallop (two sixteenth notes plus an eighth note), the heavy shuffle (Sabbath), 3/4 or 6/8 sections in the epic parts. The feel is precise but “human,” recorded without the extreme correction of modern metal.

Drums

Role

Powerful, musical drums: gallops, tom fills, a crash on every accent. Models: Nicko McBrain and Clive Burr (Iron Maiden), Dave Holland and Scott Travis (Judas Priest), Vinny Appice (Dio), Bill Ward (Sabbath, jazz swing), Cozy Powell.

Kick

• Gallop: x.xx x.xx x.xx x.xx (steps 1, 3, 4, 5, 7, 8, ...) in unison with the bass and guitars; midtempo: 1 and 3 with anticipations.
• Sound with a medium attack (2–4 kHz) and body; double kick or double pedal.

Snare

• 2 and 4, full hit with reverb; in fast songs, snare on 2 and 4 over the galloping kick.

Cymbals

• Ride on quarter notes or on the bell in the verses, crashes on the accents, an occasional china.

Interaction

• Kick gallop = bass gallop (Steve Harris) = palm-muted guitar gallop.

Sections

• Intro with toms or an arpeggio; verse with a gallop or midtempo; chorus with crashes; instrumental section with tempo changes; ending with long fills and crashes.

Fills

• Wide tom fills (McBrain), triplet rolls, fills that anticipate the guitar harmonies.

Sounds

• Large acoustic kit with ambience (1980s: room and plate on the snare), a kick with less “click” than extreme metal.

Typical mistakes

• Kick gallop not aligned with the bass; kick with extreme click (sounds modern); little dynamics.

Bass

Sound

Bass played with fingers or pick, very present and “clanky” (Steve Harris with a Precision and roundwound strings, bright sound), Lemmy with a distorted Rickenbacker and pick.

Role

• Gallops in unison with the guitar, melodic lines and countermelodies (Harris often plays the melodies together with the guitars), root notes in eighth notes.

Relationship with the kick

Gallop in perfect sync; the bass sits higher in the mix than in modern metal.

Examples

• Iron Maiden — The Trooper, Run to the Hills; Motörhead — Ace of Spades; Black Sabbath — N.I.B. (Geezer Butler's intro).

Harmonic instruments

Guitars

• Two guitarists (Murray/Smith, Tipton/Downing): Gibson Les Paul, Flying V, Fender Stratocaster, Jackson; Marshall amps (JCM800, Plexi) with moderate gain, sometimes with an overdrive in front.
• Standard tuning (Iron Maiden) or a half step down (Black Sabbath after the first albums, Dio).
• Layering: two rhythm parts, one per guitarist, L100/R100 (or L80/R80), often each doubled in the studio; third harmonies with one guitar per side; solos traded between the two guitarists (one on the left, the other on the right, or in the center).
• Palm mute in the gallops, open chords in the intros, clean arpeggios with chorus in the ballads.

Keyboards

• Synth pads (Iron Maiden of Somewhere in Time with guitar synth), organ (Rainbow, Dio), keyboards for intros.

Voicing

• Power chords, octaves, harmonized thirds, arpeggios.

Melody and vocals

Vocals

• High and powerful: Rob Halford (metallic falsetto and high screams), Bruce Dickinson (“air-raid siren,” a tenor with vibrato), Ronnie James Dio (full, operatic voice), Ozzy (nasal, distinctive voice), Biff Byford, King Diamond (falsetto).
• Epic, singable melodies, often doubled by the guitars.

Backing vocals

• Choruses sung in unison by the whole group, gang vocals, third harmonies; “oh-oh” choruses (Iron Maiden — Fear of the Dark, Heaven Can Wait).

Effects

• Generous hall/plate reverb, delay, doubles on the choruses.

Instruments

• Two electric guitars (humbuckers, Marshall).
• Electric bass (fingers or pick).
• Drums with double kick and many toms.
• High-pitched vocals.
• Occasional keyboards (synth pads, organ, intros).

Drum patterns

Synths and sounds

• Jup-8 V — 1980s pad: Supporting pad (Iron Maiden of Somewhere in Time, Seventh Son): wide saws with chorus, slow attack, under the guitars in the choruses.
• B-3 V — Organ: Heavy organ in the style of Dio and Rainbow: full drawbars, fast Leslie, drive.
• Augmented Strings — Strings: Epic, orchestral intros.
• OP-Xa V — Synth brass and pad: Pads and brass of the more melodic 1980s heavy metal (Europe, Dio).

Song structure

Form (4:00–7:00)

Mixing and mastering

Sonic goal

Wide and dynamic, less compressed than modern metal: guitars separated L/R with full mids, a defined and present bass, drums with ambience, the vocal up front with reverb. References: Iron Maiden — Piece of Mind (1983, Martin Birch), Judas Priest — British Steel (1980), Dio — Holy Diver (1983).

Kick

• EQ: HP 30 Hz; +3 dB at 60–70 Hz; −5 dB at 350 Hz; +3 dB at 3 kHz. Compression 4:1, 4 dB.

Snare

• EQ: +3 dB at 200 Hz; −3 dB at 600 Hz; +3 dB at 5 kHz. Compression 4–5 dB. Plate or hall 1.5–2 s (1980s sound), pre-delay 20 ms.

Toms and cymbals

• Big toms with reverb; overheads HP 200 Hz.
• Drum bus: 3:1, 3 dB.

Bass

• EQ: HP 35 Hz; +2 dB at 80 Hz; −2 dB at 250 Hz; +3/+4 dB at 1.5–2.5 kHz (Harris-style “clanky” sound). 1176 compression, 5 dB. Higher level than in modern metal.

Guitars

• 2 rhythm tracks (or 4) L100/R100 (+L80/R80). EQ: HP 80 Hz; −3 dB at 300 Hz; +2 dB at 800 Hz–1.2 kHz (full mids, not scooped); +1/+2 dB at 3 kHz; LP 10 kHz.
• Harmonies: guitar 1 at L40, guitar 2 at R40, delay and light reverb.
• Solos: center or on the guitarist's side, 1/4 delay, hall.

Vocals

• Chain: EQ (HP 100 Hz, −2 dB 300 Hz, +3 dB 3 kHz, air 10 kHz) → 1176 (5 dB) → LA-2A (3 dB) → de-esser.
• Space: 2 s hall with 60 ms pre-delay + 1/4 delay (−18 dB); high notes with delay throw.

Backing vocals

• Wide L/R, heavy compression, hall.

FX

• Hall, plate, tempo-synced delay.

Buses and groups

• Guitar bus with 1–2 dB; glue on the mix.

Sidechain

• Light dynamic EQ on the guitars triggered by the vocal.

Master

• Target: −10/−8 LUFS integrated (original 1980s releases −12/−10); true peak −1 dBTP.

Common mistakes

• Scooped, modern hyper-gain guitars; buried bass; vocals without ambience; master too loud.

Reference tracks for the mix

• Judas Priest — Breaking the Law (1980); Iron Maiden — The Trooper (1983); Dio — Holy Diver (1983); Iron Maiden — Aces High (1984); Judas Priest — Painkiller (1990, more modern and faster).

Reference listening

• Black Sabbath — Iron Man (1970)
• Judas Priest — Breaking the Law (1980)
• Motörhead — Ace of Spades (1980)
• Ozzy Osbourne — Crazy Train (1980)
• Iron Maiden — Run to the Hills (1982)
• Iron Maiden — The Trooper (1983)
• Dio — Holy Diver (1983)
• Judas Priest — Painkiller (1990)
• Iron Maiden — Fear of the Dark (1992)