Music theory describes notes as the pitches of sounds; these pitches can be flat, sharp or natural and represented on a fretboard as shapes which have letters assigned to them.
Chords are groups of notes played together diatonically to produce sound; both major and minor chords can exist together in harmony to produce musical tones.
Scales
Learn scales on guitar is an excellent way to understand how notes connect and chords form, quickly memorizing shapes and their interval relationships, before applying this knowledge to chords.
G major scale contains the root notes C, E and A which when played as a triad create an A minor chord. This process works for any scale pattern; all that changes is which note serves as the “root”. Learning flats and sharps will come in handy here: flat means tone has been flattened while sharp means tone has been raised – from bass string up through fretboard.
Triads
Triads consist of a root note accompanied by two intervals stacked one on top of another. The root note can either be major or minor in nature. Triads can either be closed or open – the latter type having all notes played at their lowest octaves – although duplicating and spacing does not diminish their identification as chords as long as their root note appears in the bass region.
Triads come in four distinct qualities-major, minor, diminished and augmented–that can elicit different feelings depending on the context of your song. A minor triad, for instance, might bring out melancholic or introspective elements. Triads also have inversions similar to intervals; changing its sound or feel while maintaining the same harmonic function is possible by inverting one.
Dominants
Dominant chords are an integral element in many musical styles. Constructed around the fifth note of a scale, dominant chords often take the shape of roman numeral V chord progressions to symbolize them. Dominant chords also possess a sense of tension that calls out for resolution; consequently they often signal a transition into another key by signalling with tonic notes as their final note before resolution arrives with tonic chords or starting notes for new keys.
Some dominant chords can be altered or extended to create extra dissonance and tension. For instance, in the chord progression below, when the 13th (scale degree 9) displaces 5th (scale degree 2) it creates an expectancy which is then resolved by leaping down into tonic; such nonlinear resolution is characteristic of many musical cadences across genres and used to build both tension and resolution simultaneously.
Minors
Chords on a fretboard can be formed using various techniques. Unlike piano where fingerings are relatively constant across keys, guitar chord shapes vary more freely and need some practice and learning in order to master.
One of the simplest musical forms is a minor chord, composed of three notes separated by what’s known as a minor interval. These chords often bear flat or sharp key signatures which indicate how many scale degrees have been reduced when compared with major scale degrees.
Each major key has its own relative minor key, found by counting down three half steps (major thirds) from its tonic note – in C major’s case this would be A minor. This makes an important statement about chords played in C major which will sound vastly different if played using A minor as the relative minor key.
Majors
Generally speaking, major-sounding chords tend to sound brighter and happier, whereas minor-sounding ones are darker and melancholic – this stems from major scales having major 3rds while minor scales contain flatted (3rd) intervals.
Note that in a C major progression, the first chord is known as the tonic and may end on either D or E depending on its key of music.
No matter the context, the key element to remember when learning major scales is that every interval between root and fifth equals one half step up (or down) on the fretboard. The same rule also applies when working with major and minor triads.