A triad is a group of three notes which are related by thirds. Each of the note groupings in the example below is a triad. Notice that each one is a stack of two thirds. The first group is a triad built on the note C. The triad contains the three notes C, E, and G (C to E is a third and E to G is a third-a stack of two thirds). The next group of notes is a triad built on 'D', etc.

Each of the notes of a triad is given a name. The bottom note (when stacked by thirds) is the root. The middle note is called the third and the top note the fifth.

There are four qualities of triads: major, minor, diminished, and augmented. A triad's quality is determined by the intervals it contains. For instance, a major triad contains a major third from its root to its third and a minor third from its third to its fifth. Also the interval from its root to its fifth is a perfect fifth. Click on the buttons in the example below to see the spelling for each of the four triad qualities built on the note 'F'. Pay close attention to the order of the thirds up from the root and the interval distance from the root to the fifth.

Triad Qualities Major Minor Diminished Augmented

Triads will not always be used in the convenient stacks of notes as shown above. They may appear with any note as the bass (bottom note) and with various doublings. The notes can be played harmonically (all at the same time) or melodically (notes played individually). The important thing is that all three notes are being used together in some way.

Root in the Bass

Third in the Bass

Fifth in the Bass

Root in the Bass

Root in the Bass & Root Doubled

Third in the Bass & Doublings

Played Melodically & Root Doubled

The following examples show a few ways in which triads are used in musical compositions. They are often used in an accompaniment part to support a melody, in the melody, and/or with other notes in the melody.

1. In this example a repeating C major triad (bottom staff) is used to accompany a melody (top staff). Click on the speaker icon to listen to the example.

   from Sonatina, op. 792, no. 8 by Czerny

   
   
   
   
2. In this example part of the C triad appears as individual notes in the bass accompaniment and also appears as individual notes in the melody. Taken together all three notes (C, E, and G) are present to form the C triad. Click on the speaker icon to listen to the example.

   from Carnival by Couperin

   
   
   
   

3. In the example below (from the same piece as above) the rhythm of the accompaniment is changed from eighth notes to sixteenth notes. Click on the speaker icon to listen to the example.

   from Carnival by Couperin

   
   
   
   

4. In this example the notes of the C minor triad are first played individually in the first two measures and then together in the final three chords with Eb (the third) as the bass note (Notice that the clef of the bottom staff of the third measure changes to the treble clef.) Click on the speaker icon to listen to the example.

   from Sonata, K. 457 by Mozart

   
   
   
   

You should be able to spell any of the triad qualities with any given note as the root. Of the seven triads which are spelled on natural notes (no sharps or flats) three are major, three are minor, and one is diminished.

To make a major triad minor lower the third a half step.
To make a major triad diminished lower the third and fifth a half step.
To make a major triad augmented raise the fifth a half step.

To make a minor triad major raise the third a half step.
To make a minor triad diminished lower the fifth a half step.
To make a minor triad augmented raise the third and the fifth a half step.

To make a diminished triad major raise the third and fifth a half step.
To make a diminished triad minor raise the fifth a half step.
To make a diminished triad augmented raise the third a hald step and the fifth a whole step.