Chords are the basic units of harmony. A chord is an organized group of three or more simultaneous pitches. Any combination of pitches sounded simultaneously can be considered harmony, but chords are organized according to the intervals they contain and by the way they behave in relation to each other.


A triad is the most basic chord. A triad consists of three pitches (no more, no less) and is built by stacking major and/or minor thirds. The bottom note of a basic triad is known as the root. The middle note is the third because it is a 3rd above the root, and the top one is the fifth because it is a 5th above the root.

root, 3rd, and 5th in triad

The qualities of the thirds (major or minor) used to build a triad determine the quality of the chord itself. The interval between the lowest note and the highest note of a major or minor triad is a perfect fifth, but the inner intervals differ. A major triad has a major third on the bottom and a minor third on the top, whereas a minor triad has a minor third on the bottom and a major third on the top. A triad that consists of two minor thirds is a diminished triad, and the interval between the lowest and highest notes is a diminished fifth. A triad that uses two major thirds is an augmented triad, and the interval between the lowest and highest notes of this triad is an augmented fifth.

Major Triad Minor Triad Diminished Triad Augmented Triad
perfect fifth minor third perfect fifth major third diminished fifth minor third augmented fifth major third
major third minor third minor third major third

Triad Qualities


When the notes of a chord are played in sequence rather than simultaneously, we call this an arpeggio. Arpeggios are used in place of block chords (where all pitches are played simultaneously) in order to add rhythmic movement in a place that is harmonically static. Composers often give arpeggios to instruments that are not able to sustain pitches for a long period of time (examples: harpsichord, harp, guitar) because the pattern they create allows the same note to be sounded over and over again, giving the impression of a sustained pitch. This illusion of sustain allows the sequential pitches in arpeggios to imply a simultaneous chord.

Arpeggiated Chords

"Music is nothing else but wild sounds civilized into time and tune." - Thomas Fuller

"After silence, that which comes nearest to expressing the inexpressible is music." - Aldous Huxley

"Music in the soul can be heard by the universe." - Lao Tzu

"Music is a higher revelation than all wisdom and philosophy." - Ludwig van Beethoven

"Music is the movement of sound to reach the soul for the education of its virtue." - Plato

"Music expresses that which cannot be said and on which it is impossible to be silent." - Victor Hugo

"Music is nothing else but wild sounds civilized into time and tune." - Thomas Fuller

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