Fundamentals
17 Triads
Chelsey Hamm
Key Takeaways
- A triad is a three-note chord whose notes can be arranged in thirds. A triad can always be “stacked” so that its notes are either on all lines or all spaces.
- When stacked in its most compact form in thirds, the lowest note of a triad is called the root, the middle note is called the third, and the highest note is called the fifth.
- There are four qualities of triad. A major triad's third is major and its fifth is perfect, while a minor triad's third is minor and its fifth is perfect. A diminished triad's third is minor and its fifth is diminished, while an augmented triad's third is major and its fifth is augmented.
- In chord-symbol notation, major triads are represented with capital letters that correspond to the triad’s root. Minor triads have a lowercase “m” after the letter, diminished triads have a lower-case “dim” or a degree sign (“°”), and augmented triads have a lower-case “aug” or a plus sign “+.”
- Within major and minor keys, triads have particular qualities that correspond to scale-degree. These are the same in every major and minor key, which makes memorizing them useful.
- Triads are identified by their root, quality, and inversion.
Triads
The three notes of a triad can always be arranged in thirds. melodically and harmonically:
shows two triads, each written both
The first triad is shown on three adjacent spaces, while the second triad is shown on three adjacent lines. A triad can always be “stacked” so that its notes are either on all lines or all spaces.
When a triad is stacked in its most compact form (measures 2 and 4 of
), it looks like a snowperson. shows several snowpeople:A snowperson consists of a bottom, middle, and head. Likewise, a triad consists of a lowest note, a middle note, and an upper note. Colloquially, when a triad is stacked in this fashion it is sometimes called “snowperson form,” but non-colloquially it is known as root position; this is explored more in the the chapter titled Inversion and Figured Bass. The lowest note of a triad is called the root, the middle note is called the third, and the highest note is called the fifth. shows this:
As you can see in
, the third is so named because it is a generic third above the root, and the fifth is so named because it is a generic fifth above the root. The root is analogous to a snowperson’s bottom, the third to its middle, and the fifth to its head.Triadic Qualities and Listening to Triads
There are four qualities of triad: major, minor, diminished, and augmented.
shows these four qualities of triad, each with a root of F and their quality of fifth labeled, while shows these qualities with their quality of third labeled:As seen in , a major triad's fifth is perfect and its third is major, while a minor triad's fifth is perfect and its third is minor. A diminished triad's fifth is diminished and its third is minor, while an augmented triad's fifth is augmented and third is major. Major, minor, and diminished