How to Play Non-Diatonic Chords in a Major Key

Many songs feature chord progressions that do not conform to the scale underlying major keys. Notes which remain within this range are known as diatonic while ones which extend outside it are known as non-diatonic.

Most songs written in major keys tend to feature an upbeat, cheerful feel, often as the result of subject matter rather than chord choices alone. Let’s consider some examples to demonstrate this point.


A triad is any chord made up of three or more notes and distinguished by the intervals between its parts; typically any notes from any major scale, it’s defined by major, minor and diminished interval types as defined by its quality of intervals between its root note and third and fifth notes respectively.

A major triad is formed by selecting the first, third and fifth scale degrees of any major scale as its starting points. It consists of two notes separated by major thirds while its upper two notes are separated by minor thirds. A major triad is further distinguished based on its interval quality between its first and second scale degrees as well as between fourth and fifth scale degrees.

Triads are named according to their type and quality of intervals; those formed on scale degrees I-IV-V are always major chords; those formed on degrees II-III are minor chords; while those formed between VI and VII are diminished chords.

To identify a triad, write its root on the staff and add any accidentals required by its key signature next to it. Next, draw notes a third and fifth above its root (i.e. a snowperson). Finally, for major scale degrees spell out its name with Roman numerals which correspond with its scale degree of construction.

Once you understand the names of basic triads, they can be created in any major key using their naming conventions to spell out each chord on any staff. Once completed, these triads can be played either all at once as blocked triads or one note at a time as broken triads.

As you create triads in different keys, it becomes evident that their sequence of major and minor chords remains consistent: chords constructed on scale degrees I-IV are always major; chords built on II-III will always be minor; those on VI and VIII will always be diminished.

Dominant Chords

As its name implies, dominant chords are formed using the dominant scale degree of a key. For major keys this usually means one that’s five degrees above the tonic chord. You can also alter other chords to sound dominant — this technique is known as secondary dominants. For instance, adding an extra seventh can change a D minor chord into G dominant (C-F#-A-C). This additional seventh adds tension and drama that makes this chord even more effective than one that simply stays D major.

Dominant chords create a sense of anticipation in music, which is then alleviated when their natural resolution to the tonic triad (root note of key) takes place. This effect can be found across genres and often appears at the end of musical phrases or cadences – it’s a powerful way to tie up musical ideas expressed within one phrase or section of song.

Dominant chords are powerful tools for reinforcing and solidifying key, while also being useful when it comes to modulations. By including the dominant seventh of a new key as part of their modulation plan, songwriters can provide listeners with a gentle “push” towards it allowing them to adjust smoothly into it.

Dominant chords offer another benefit in that they can harmonize with all but the submediant tones in a major scale, giving songwriters plenty of creative freedom when choosing chords for songs. This gives songwriters great freedom when selecting different kinds of chords within one tune.

As you explore these types of chords, it is important to keep in mind that any chord can become dominant by simply altering its notes. While this might seem scary at first, changing chord notes is actually quite useful! Additionally, it’s essential that you distinguish between primary dominants and secondary dominants so you know their effects on you as an artist.

Half-Diminished Chords

Diminished seventh chords are an integral component of a jazz guitarist’s toolbox, being used both as passing chords and bridges between dominant chords. This type of chord is usually represented in chord charts by its acronym Xo7 or Cm75. A diminished seventh is composed of a three-note triad where its root has been reduced from its usual level (bb) with an added fifth added that gives this chord its distinctive bluesy sound; making it highly adaptable across many genres from jazz to blues to metal music!

Half-diminished seventh chords are another subtype of diminished chord. Similar to its fully diminished counterpart, but lacking a Bb note, they’re typically used as leading-tone chords or passing chords within bebop progressions as leading-tone or passing chords; alternatively they can function in dominant function preceding diatonic V chords – frequently found in progressions like CM7 – F#dim7 – Gm7.

Minor ninth chords may not be as prevalent, but they’re an effective tool for adding tension and color to a progression. Notated as either “m9, min9 or -9”, minor ninths are basically major triads with both a seventh and a major ninth note – you may hear these chords featured on songs by artists as diverse as Blur, Katy Perry or John Mayer.

Minor ninth chords can be challenging to play on guitar, so regular practice is essential. Begin by starting small by practicing it on one set of strings at a time until you feel confident with playing it all over the fretboard – and don’t forget all key variations, to familiarize yourself with its various voicings!

Suspended Chords

Suspended chords are an effective way of adding tension and dissonance to a progression. They are a form of triad in which either the third or fourth note has been replaced by either an alternate second or fourth tone, creating a unique sound that can effectively add musical tension – something often utilized by classical composers as transition between more conventional chords.

Suspended chords come in two main varieties, the suspended second (sus2) and suspended four (sus4), both originating during 16th century Renaissance composers’ experiments with dissonance-producing intervals such as second or fourth intervals that dissonant more than major or minor third intervals – creating tension with such dissonant intervals that create sounding ‘open’ or uncommitted, as people expect for it to resolve, yet may leave them wanting more.

Utilizing sus chords to generate tension is easy, since no special training or knowledge are needed to use one effectively. Simply replace the third of a major triad with either an alternate second or fourth and create sus2 or sus4 chords; our ears will still hear it as a triad but our brains expect for it to resolve, creating musical tension and anticipation!

The Police’s song Message in a Bottle utilizes multiple suspended seconds and chords within an arpeggiated guitar riff to create anticipation and musical tension as these chords don’t resolve, yet still sound beautiful while creating mood. Suspended chords can also serve to separate sections of music while giving an impression of forward momentum.

Prince’s Purple Rain offers another fantastic example of using sus chords to build tension by refusing to resolve it and leaving listeners hanging, providing an effective means of adding emotion without overusing power chords.