A chord consists of three or more notes connected by chord progressions that relate directly or indirectly to the Major Scale. When we speak of major chords, this refers to ones in which all individual notes reference it directly or indirectly.
Chords are constructed using intervals that ascend by thirds (two or more). To find their formula, begin with the root note and count up through each scale degree until reaching a seventh chord.
Root Note
Root notes of chords are known as roots. You can usually determine the rest of a chord’s composition by starting from its root note and looking at what intervals lie stacked upon it – for instance major chords typically feature both major third (alphabetically two half-steps) and perfect fifths (2 semitones).
Minor thirds, diminished sevenths and ninths can add extra flavor to a chord – these “extended chords” can be added to any one of the other three types for a unique combination.
Chords containing five notes or more are another common sight across genres of music, often known as triads and determined by intervals between notes that determines their sound quality.
Quick tip to remember when counting intervals between notes: They are measured in half-steps. For instance, G and B are separated by four half-steps or seven semitones – this makes learning how to count notes within scales as well as using chord formula essential.
Third Note
Major chords feature three notes that are one second above their roots, so musicians may use interval names (C to E) to identify major chords; adding sevenths or eights such as C7 or G8 for extended chords can also help identify major chords. Intervals can also be classified alphabetically: C to E is considered a major third while C to G is classified as minor seventh.
To construct a major chord, start at the root and move along by placing your index finger on the third, index finger on the fourth note (4 keys from the root, counting both black and white notes) then placing thumb and middle finger on fifth (5 keys to the right of root). Roman numeral analysis makes this easy – major chords will be 1, minor chords 2, while an augmented chord has its top note raised one semitone (+4 semitones), giving an anxious and suspenseful sounding result.
Fifth Note
Those learning chords should first gain an understanding of how they’re constructed. Simply knowing what a chord looks like is not enough; understanding its formulae will take much more practice.
Root Note of a Major Chord The root note of a major chord serves as the cornerstone of its formation, defining both its letter name and quality (major or minor).
Each number in a scale represents an interval, the space between notes. A sharp on an interval raises it by half steps while flattening an interval lowers it by the same amount.
Major chords contain three notes. The third note, designated by its letter name, determines its quality – major or minor. Alternately, you can replace one of them with a fourth to create Csus2 or Csus4 chords.
Seventh Note
To create a major seventh chord, add one note from its related scale to your existing major triad – for instance G (root), C (major third), E (perfect fifth) and F# (seventh). An easy way to memorize major scale degrees would be counting up from root to seventh by semitones; two semitones brings B, three semitones brings D etc.
Addition of the seventh note to a major triad produces a dominant seventh chord, often used in music to add tension before returning back to its root note and resolving. For further complexity you could build a diminished seventh chord by adding minor third and a flattened fifth like Cmd7(add5) for instance; this produces what is also referred to as half-diminished seventh chord and creates a very tense soundscape.