Chords are composed of the first, third and fifth notes from any major scale; this formula applies across every key.
Intervals, or distance between notes, influence the sound of chords. For instance, two C’s sound major, while three G’s make for a minor sounding chord.
Triads
Triads form the building blocks of every chord. Triads consist of groups of three notes stacked a third apart – for instance, in C major, they consist of the root note at its base note, the major third in its center position, and finally a perfect fifth at its apex note.
A triad can be created on each scale degree of the major scale. A major triad constructed at scale degree 7 would be known as an “viio chord.”
To create a triad, start by drawing its root note on a staff, adding notes a third and fifth above it (i.e. snowperson), then any accidentals from its key signature to create your chord of choice. Major triads are identified with capital letters that correspond with its root note while minor and diminished ones are designated with lowercase “mi” in front of their letter, with diminished ones showing as reduced versions with ‘d’ as their symbol.
Triad Inversions
Once you understand basic chords, it is time to move onto inversions – the practice of switching the order of individual notes within them.
Triad inversions can be used to create various types of chords. One type is a seventh chord, which combines a major third with the minor seventh degree; and another type, C seventh chords combine major second with fifth degree of major scale to produce different kinds of chords.
Each chord can have up to two inversions. The initial inversion changes the order of its bottom notes; for instance, inverting a root-position C triad by moving its lowest note up an octave yields C E G as an inverted chord.
The second inversion involves altering the top note. For instance, a root-position B triad can be inverted by changing its top note from B to C; this process is commonly referred to as the “B major” inversion. There are piano diagrams available that display all four interval qualities (diminished, minor, major and perfect), along with their note interval names and positions and final chord note spellings.
Major Third
No matter whether you’re building a major or minor scale chord, the first three notes always remain constant – they represent the 1st, 3rd, and 5th notes from their corresponding major scale. Even when moving these notes up or down an octave they will still form one chord.
This holds true for scale degrees as well. A major third is four half steps higher than its root note while two semitones lower is called for in diminished fourths.
This interval gives a chord its major or minor sound quality. A major scale has an interval of one major third between its tonic and mediant scale degrees while minor scales use one minor third between their tonic and mediant scale degrees – this difference distinguishes major and minor keys as well as their tonic triads in either key type; transposing chord progressions is made easier because their formula remains the same no matter which key is being played in.
Perfect Fifth
The perfect fifth is an interval that occurs above the root of a major chord and is one of the most consonant intervals in any scale, thus being used to build many major chords. Music theory defines it as seven semitones. A perfect fifth consists of two notes separated by one white key with no black keys between them – perfect fifths also serve as the basis for all minor chords as well as most triads in the circle of fifths.
As you traverse the circle of fifths, observe that each successive major scale contains more sharps than its predecessor; this is because each successive major scale adds the 7th degree to its scale; therefore C minor contains three sharps while D major has only two.