How to Build Major Diatonic Chords

Beginner piano students often struggle to understand how chords work. Jonny shows you how to build diatonic chords using simple naming conventions in today’s Quick Tip video.

Diatonic chords are those which originate in one particular key. Gaining an understanding of diatonic relationships will make playing diatonic chords much simpler.


Today’s Quick Tip video offers a template to illustrate that chords in major keys that do not contain any flats or sharps are known as diatonic chords, meaning they belong to that key and don’t contain any flats or sharps.

Musical scales contain seven notes that form potential chords. Chords are constructed by skipping certain number of half steps up or down a scale to create their tonic tone; diatonic chords utilize only their starting tones from specific scales for easy recognition by our ears. Chord symbols often include sharps or flats to alter an interval quality but this won’t alter its ‘root’ in key.


In a major key, chords constructed on the first three scale degrees will always be major; those constructed on sixth and seventh degrees may be minor; similarly, minor keys often feature chords built upon four scale degrees which tend toward minor while fifth degree chords often fall under diminished category.

Triads are constructed using intervals. The distance from root to third and from third to fifth forms a major interval; while between third and fifth lies another minor one (for more on this subject please visit Ear Training – Interval Crash Course).

As such, chords derived from these scale degrees will all be diatonic; this feature makes harmonizing by ear easier as many songs only use chords from one particular key.


Diatonic chords refer to chords which are native to one key. For example, chords that use notes in C major scale would be diatonic to that key.

Harmonizing melodies usually employ diatonic chords in their same key; however, non-diatonic (also known as chromatic) chords can add additional color and variety to a harmony’s arrangement.

Learning a new key without understanding its diatonic chords is like trying to learn another language without understanding its syntax: you may recognize some words but may struggle with communicating intelligibly. Diatonic chords provide a framework for building songs in any key – which can come in particularly handy when arranging melodies or creating chord progressions by ear.


If you have an idea for a melody, diatonic chords can help you harmonize it more efficiently and transpose melodies into different keys.

Note that just because a chord contains a flat before its Roman numeral does not equate to having an associated note name that begins with “Gm”. For instance, C minor’s III chord contains a flat before its Roman numeral, but that does not imply that its root note must also contain Gm.

Minor keys contain thirteen possible diatonic triads, with the diminished seventh being an exception. We will explore this chord as well as V and VI chords of harmonic and melodic minor in our next lesson – learning this framework will enable you to create song progressions by ear!


Contrary to major and minor chords, augmented chords do not include any flats or sharps; thus they derive their roots from a key’s major scale but do not qualify as diatonic chords.

These chords can help create harmonic tension and progression while adding an unexpected chromatic hue to your music. In addition, they work very effectively as leading chords for half cadences or authentic cadences.

Augmented chords are an exceptionally versatile type of triad found across all genres of music. Their captivating structure and mesmerizing sound can transport listeners into another dimension of musical delight; whether used as a dominant substitute or linear passing chord with linear function function, an augmented triad should be an essential tool in every musician’s harmonic toolbox.