Trent Reznor Chord Theory


Whether it’s in his music as Nine Inch Nails, his soundtrack work in collaboration with Atticus Ross, or with How to Destroy Angels, Trent Reznor’s sound is always uniquely identifiable. Although part of this is due to his sound design, involving digital distortion and noise processing a variety of sound sources, his use of harmony, chords, and melody also has a major impact on his sound. Reznor’s music has a distinctly anxious tone that sets the scene for his often bleak lyrics. In the film Sound City, Reznor explains that he has a music theory foundation, specifically in relation to the keyboard, and this subconciously affects his writing. I’ll look at some carefully selected examples of Trent Reznor’s songwriting, and try to figure what he does to make his musical parts so unique sounding.

“My grandma pushed me into piano.  I remember when I was 5, I started taking classical lessons.  I liked it, and I felt like I was good at it, and I knew in life that I was supposed to make music. I practiced long and hard and studied and learned how to play an instrument that provided me a foundation where I can base everything I think of in terms of where it sits on the piano… I like having that foundation in there.  That’s a very un-punk rock thing to say. Understanding an instrument, and thinking about it, and learning that skill has been invaluable to me.” - Trent Reznor (Sound City)

Minor Keys

Music theory can be confusing, and multiple schools of thinking (classical, jazz, modal), along with multiples names for the same thing contribute to this. I’ll use both music notation and piano roll to illustrate the musical concepts, but to quickly sum up some terms I’ll use:

  • A scale is a series of notes that starts and ends on the same note. Commonly, scales have 5 or 7 notes.

  • A key is the chord a piece resolves to. A piece that resolves to a C Major chord is in the key of C Major. If the piece is entirely diatonic (in key), then the melody and chords will all be notes from the C Major scale.

  • The natural minor scale is a series of notes that have minor, or flattened degrees, specifically a b3, b6 and b7. In contrast with the major scale, it has a sombre sound, thus the name.

  • The dorian scale is a minor scale that has a natural 6th, instead of the flattened 6th found in the natural minor scale. This gives it a brighter sound, whilst still retaining a minor tonality. Note that it should really be referred to as a mode instead of a scale, but that’s outside the scope of this article, so I’ll call it a scale.

  • The term, minor key is more complex, and refers to any scale that has a minor third, but variable 6th and 7th degrees. By changing these 6th and 7th degrees, you can create new flavours.

  • A relative major or relative minor are keys that contain the same notes as another key. For example the C Major scale (C D E F G A B C) has the same notes as the A Natural Minor scale (A B C D E F G A). Despite having the same notes, they are different keys because of the ways they resolve, which is typically done by starting or ending on a certain chord.



I’ll start by looking at Mantra, from Reznors appearance in the film Sound City. The song is a jam between Reznor, Dave Grohl and Josh Homme, and the results are predictably inspiring. The songs extended outro, beginning at 4:47, involves a repeated bass pattern in E. Over this static bassline, Reznor adds a Wurlitzer chord part that chromatically moves between major, minor and suspended tonalities of E. This choice of inter-key movement perfectly illustrates Reznors gravitation towards chromatic harmony, and results in a simple musical part that instantly sounds like Trent Reznor.


The Harmony Begins to Blur

The Line Begins to Blur also blurs the line between major and minor, with a progression that starts C | Bb | F, which is a V-IV-I sequence in the key of F Major. The chord progression ends on D Major, which is entirely outside the key of F, although it only borrows one outside note, F#. The outside chord gives the progression a harmonic ambiguity, and a powerful feeling of tension that must be resolved each time the progression repeats. Instead of fully resolving with the F chord, the music still feels restless. Note that the harmony is mostly fleshed out by the guitar part, which takes advantage of the chromatically rising E-F-F# line.

Line Blurs-1.png

The Minor / Dorian Switch

One of Trent Reznor’s signature tricks is to work in a Minor Key and switch between one with a Minor or Major 6th. In the key of D Minor, these notes are Bb and B Natural, implying the Natural Minor and Dorian scales, respectively. As mentioned earlier, you just need to know that a Minor Key with a Major 6th sounds brighter than with a Minor 6th. Compositionally, a song composed purely in D Natural Minor would use a Gm and Bb chords, and a song composed purely in D Dorian would use G Major and Bdim instead. Here’s a comparison, I personally feel that the Dorian has a smoother, cooler sound than the sombre sounding Natural Minor scale.

Natural Minor Dorian.png

Beside You In Time

Beside You in Time is in D minor, however it switches between these dorian and natural minor tonalities to create a harmonic twist. We start with a D minor chord, and move from there to a Bb major chord, giving us the natural minor tonality with a Bb note. The following chord is the twist, a G major chord, which comes from the D dorian tonality and has a B natural note. This sequence creates a chromatic rise of A (the 5th in D minor) to Bb, to B natural.

Beside-You in Time-Nine-Inch-Nails-Sheet-Music.png

Right Where It Belongs

Right Where It Belongs picks up from right where Beside You In Time ends, staying in D but transitioning to D major… kind of. Although the piano motif in bars 1 and 2 starts of with a D major chord with an F# melody note, bars 3 and 4 switch to D minor chords and melody, using an F natural note instead. This constant shifting between D major and D minor, which can be interpreted as happy and sad, gives the music a constantly shifting feeling, which helps give the album closer its emotional vibe.

Right-Where it Belongs-Nine-Inch-Nails-Sheet-Music.png


09 Ghosts I, from the four disc dark ambient work Ghosts I–IV, uses the same Natural Minor-to-Dorian trick. The song is in C minor, a tone lowering than Beside You In Time, but the chords follow the same progression. The chord progression ends with an Ab chord, which implies C natural minor, followed by an F Major chord, from C dorian. The melody uses an A natural note, but Reznor is careful note to use it over the Ab chord, to avoid a clashing note. Reznor is aware of music theory, so is likely conscious of this harmonic trick.


More Ghosts

02 Ghosts I uses the same technique to create an uneasy dark ambient feeling, setting up the scene for the rest of the album. Here the key is Eb major, the relative major key of C natural minor, so it uses the same notes. The piece uses melodic lines played over a constant drone of Eb, and alternates between A natural notes, a tritone away from Eb, and the much more stable sounding Ab, to cleverly shift between tonalities.

Ghosts II-1.png

March of the Pigs

Going back to Reznor’s breakthrough second album as Nine Inch Nails, 1994’s The Downward Spiral, Reznor definitely had harmony in mind, as well as motifs. The line “nothing can stop me now“ is repeated on three tracks, and there is also a recurring melodic motif that appears in Piggy, Closer and The Downward Spiral.

The breakdown in March of the Pigs is built on a bassline of D | Ab | G | F. The part is sparse with little other melodic content, however Reznor’s vocal melody adds extra notes that slightly flesh out the harmony, and I’m interpreting the progression as Dm | Ab | G | Fm. The progression is unusual because the second chord is a tritone away from the first chord, giving it that quasi-evil tone that bands like Black Sabbath love.

March-of the Pigs-Nine-Inch-Nails-Sheet-Music.png


One of the coolest melodic parts in Closer is an ascending line that plays after the first chorus, at the 1:25 mark. The bass part moves between C and Bb chords, implying a C or F tonality. The melodic line ascends the notes E | F | G | Ab, with the last note being intentionally ‘out of key’ to give an exotic sound. It could also be interpreted as being borrowed from a C minor, implying a major to minor switch as the line ascends.


What makes things stranger is that the line is harmonised chromatically in major 3rds (descending) for every note, which introduces even more ‘out of key’ notes, and sounds characteristically Nine Inch Nails. The lower harmony is quieter in the mix, and is a subtle touch. This is very different approach to the usual western technique of harmonising in diatonic thirds.


Technically, Missing

Technically, Missing, from Trent Reznor & Atticus Ross’ Gone Girl soundtrack features a clever mix of major and minor. The song is in D, and the melodic part is intentionally vague about being major or minor, as it doesn’t touch the 3rd. The bassline does however, moving from an F# that implies a D major chord over an F# root, to an F, that implies an F major chord, that would come from a D minor key. The switch in harmony is subtle but effective, and primarily works because the composition doesn’t use the 3rd for the melody.

If you’re interested in reading about some of the synth patches uses in the Gone Girl soundtrack, check out my article, Recreating Trent Reznor and Atticus Ross' "Gone Girl" Score With Software Instruments.


Shit Mirror

Shit Mirror, from this years Nine Inch Nails release Bad Witch, throws all the harmonic rules out the window, opting for a largely chromatic chord progression. The songs progression starts in A major, implying that the song will be in the key of A major, but the next chord is F major. This could be from the A minor key, implying a switch from major to minor, just as in Right Where It Belongs. The next chord is Eb, which has nothing to do with either A major or A minor. Here the harmonic tricks have been ignored, thrown out the window, instead Reznor has used a completely unrelated chord. It may not adhere to any music theory rules, but it simply sounds good, so it works.


The End

Thanks for reading, comment below with any songs you think I missed! If you want to download the MIDI files from the examples, simply click the button below, and be sure to subscribe to my newsletter to stay updated on new articles!

“When I’m writing music today, rarely do I sit down and think ‘Oh, this should resolve to that’, I don’t think of that shit.”

“But subconsciously, I know I do.”