Harmonic mixing

2022, Jul 17    

When composing, producing or mixing it adds something to think about the tonality (how keys relate to one another) and harmony (how chords are composed from a key) of songs. The amount of harmonic information and interest in a song can vary a lot - the single descriptor of “key” doesn’t give much away about what to expect. This post is to give an introduction to the basics of harmony, how to listen to it in a song, and how to use it while mixing.

All examples below are just random songs from my library to elucidate the points made.

Introduction

A few situations where harmonic information can be useful in mixing below. The below introduction won’t all make sense the first time until having read Fundamentals!

Note: being able to listen to harmony and understand what is going on requires training of the ear, especially towards point (4) below. Something that helps is ignoring the percussion, and listening to how the harmony (if it exists) gives interest to the song - e.g. around drops. Hopefully the common scenarios in Common chord movement can help to gain a feeling.

  1. Mixing tracks on percussion. No harmonic information - a lot of club-ready tracks might have intros/endings of solely percussion so you do not have to think about harmony.

  2. Mixing tracks on sparse harmony. Limited harmonic information…

    a. Example: Bubas Producoes - Padjinha Pt. 3

    All melodies in the song only consist of 2 notes (B and A) and there is no harmony (no chords under the melody to suggest a key). Therefore no matter what key is “detected”, you can use this information to e.g. mix into other songs in keys whose scales contain these notes, such as G major or E minor (among others) - see Tonal Matching below.

    b. Example: Logic1000 - Baddie Pt. 2.

    Very sparse melody composing of few notes + sub-bass all around the key centre - it’d be safe to mix to any related key to the “detected” key - see Tonal matching below.

  3. Mixing tracks with very simple but full harmony. a. Example: Groove Armada - Superstylin’.

    There is full harmony in the melodic instruments, but it stays put on the chord of A major - the harmony does not move at all. You can mix in harmonic information from another track at any point in the track. However, it might help to understand what keys follow naturally after A major - see Common chord movement.

  4. Mixing tracks with moving chord progressions and full harmony. Harder as have to a) think about how the chords are being used throughout the song, and how to relate these to new ones when mixing, and b) constantly pay attention to where you are in the chord progression.

    a. Example: KH - Looking at your Pager - the harmony is especially prominent at 1:25 on this SoundCloud.

    A very simple 4-chord progression Bm-F#-F#-F#.

    The first chord, Bm is the tonal centre (1) of the song (even though it is the least frequent chord), and F# is the dominant (5), which builds tension throughout the chord progression, and releases on the next Bm. Listen to how the harmony releases tension on any drop throughout the song. However, if mixing this on a double drop and the other track does not use the dominant to build tension, the build-up before the drop could seem quite confusing.

    b. Example: SpectraSoul - Say What (Midnight Mix) - e.g. at 0:44 and at 2:36

    A much more complex, jazzier 4-chord progression with a funky twist every so often F#m-E-D-C#.

    Nevertheless, the final chord C# is still the dominant (5) chord which provides the tension.

Fundamentals

Listening to chord movement

Important to be aware of all of below, even if just for historical context:

Chord progressions

In 20th century Western music, due to cultural reasons of music consumption and with the coming of jazz, as well as in other contemporary world music, the previous, “intellectual” art (classical) music was replaced by music with more regular chord patterns, that repeat every, e.g. 2, 4, 8 or 16 beats. The chord pattern is always based on a tonal “centre” or the key of the song, and other chords in the pattern move to create interest and tension.

Examples:

  1. 2-chord patterns, such as: a. A lot of reggae/dub songs with the common skank pattern. In Gentleman’s Dub Club - High Grade the chord pattern is just 1 and 5 (Gm-D), where each chord is 4 beats.

    b. Four Tet - Lush where the pattern is C#m-G#m-C#m-G#m (again 1 and 5) where each chord is 4 beats, and the second C#m is very subtlely modified in the bassline.

  2. 4-chord patterns, such as the SpectraSoul track above.
  3. Other, such as Overmono - Everything U Need - a pattern where the chords don’t move with the bars…

Modulation and mixing

In many celebrated forms of Western art music, such as the sonata, modulation was to change the tonal centre of a piece to give more interest. For example, the sonata form of the 18th-19th centuries was based on strict rules of when and where to modulate.

Similarly, some pop songs shift key in the middle of the song to keep people listening - for example, in Michael Jackson - Man in the Mirror the key shifts up a semitone at 4:49 of this remix:

Similarly, many songs with a verse-chorus structure shift key temporarily between verse and chorus, such as in Mark Ronson/Amy Winehouse - Valerie, where the song moves to the subdominant (4) key in the bridge to build tension for the chorus, e.g. at 0:27 in this cover:

Similar ideas can be applied when mixing, to keep some coherence of harmonic information and movement between tracks, as opposed to mixing on just rhythm.

Basic harmony theory

Central to understanding harmony theory is being confident in recognising the major and minor scales in all keys (even if it doesn’t seem important). This allows you to calculate how other notes and keys relate to your current key: for example, if the current key is G major, knowing the G major scale allows you to calculate what other keys relate to G major (e.g. that D major is chord 5, and C major is chord 4).

It seems like a lot at first, but the more you practise, the more the “language” or “grammar” of harmony becomes second nature.

Note names

See this Ableton guide and keyboard guide for a refresher on note names.

Chord names

C = C major. Cm = C minor. Out of scope: C7 = C dominant 7th - read here.

Scales

In a major key, notes tend to follow the major scale. Once you’ve got these down, you can calculate the “degrees of the scale” easily, of which the following are most important, e.g. for C major:

  • C: tonic or 1st degree of the scale, i.e. the tonal centre.
  • F: subdominant or 4th degree of the scale. If you think about it the other way round, C is the dominant or 5th degree for F; that’s why F is called the subdominant.
  • G: dominant or 5th degree. The most important degree - the dominant creates the most tension and resolves most naturally into the tonic. In the below, the G major triad moves to the C major triad; note by note, the B resolves to C on top, the G stays the same, and the D resolves to E.

Demo 1: 5-1 in the key of C major

In a minor key, notes tend to follow the natural minor scale. Note that the difference is that the 3rd, 6th and 7th degrees are flattened (lowered by a semitone).

Triads

Given yourself a key from above, how do you make a chord? Most (theoretically all) chords are based on the triad - the 1st, 3rd and 5th degrees of the scale. In Demo 1, the G and C chords both have all the notes of their respective major triads. The minor triad obviously differs in the 3rd degree, giving the “darker” or “sadder” sound, in Demo 2a.

Play around here. It becomes obvious that every note is part of 5 triads: major and minor for where the note is the tonic, major for when it is the third, and major and minor for when it is the fifth.

Common chord movement

Here are some common patterns for chord movements which are useful to know. I think that they are built on either of two concepts: tension and release, and tonal matching.

Tonal matching

  1. Moving from a major key to its relative minor key (or vice versa). The “relative minor”, or 6m, is the minor key that is the most related to a major key, since their scales are exactly the same. For example, Am is the relative minor of C major; the Am and C major scales are the same, and the Am triad and the C major triad have two notes in common. (Similarly, Eb major is the relative major for C minor). See Demo 2b. This means that when mixing from one to the other, it’s less likely to hear notes that clash. This is so common that the inner ring of the Camelot wheel shows the relative minors of the outside major keys.
  2. Moving from a major key to its own minor key (or vice versa). This makes sense, as the tonic does not change at all, for example C major - C minor. If one track ends on the tonic note and the next track starts on the tonic note, then it will seem seamless. See Demo 2a. However, if notes of the scale such as the third degree are very present in the melody, there might be a clash between the major third and minor third.

Demo 2: a): C major and its own minor key (C minor). b) C major and its relative minor key (A minor).

Tension and release

  1. 5-1, which, when at the end of a phrase/pattern, is called a “perfect cadence”. (e.g. G-C or G-Cm) Why it works is shown in Demo 1. This is so common that it is immortalised in the circle of fifths: consecutive perfect cadences equals moving down the circle of fifths.

  2. 7-1m, or 5-6m. Quite popular for keeping a dark feeling in minor-key songs. This is called an interrupted cadence - instead of 5-1, the relative minor (6m) “interrupts” the resolution of the tension.

    Demo 3: interrupted cadence in key of C major

  3. 4-1, which, when at the end of a phrase/pattern, is called a “plagal cadence”. (e.g. F-C). Note that this can also be seen as the inverse of a perfect cadence, or moving “up” the circle of fifths.

    Demo 4: 4-1 in key of C major

    Less popular now in popular music. One important usage is in the famous 12-bar blues pattern, which ends on a plagal cadence in bars 10-11, for example in the below (the pattern starts at 0:08):

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