Triad VS Seventh Chord

As is well known, a chord consists of three or more notes played simultaneously.
Only a single note would simply be “a note.” Two notes are simply “two notes” or an “interval” and from three notes onwards, we speak of a chord.

The Triad

A triad consists of the root, the third, and the fifth, i.e., the first, third, and fifth notes of the scale.

- The root determines whether it is an F, a G, a D, an A, or any other letter from A-G. 🙂
- The third indicates whether it is a major or minor chord.
- The fifth is a more or less useless note that is often omitted, but still makes the chord complete.

A list of possible combinations of a triad:
(Of course, it is assumed here that the root is played every time anyway)

Major third = Major (e.g., D)
Minor third = Minor (e.g., Am)
Major third + augmented fifth = Augmented chord (e.g., Gaug (aug = augmented))
Minor third + diminished fifth = Diminished chord (e.g., Fdim (dim = diminished))

In addition to its function as a referee between major and minor, a third can also be replaced by a second (sus2) or a fourth (sus4).

The Seventh Chord

A seventh chord is a chord that contains four notes. In addition to the three notes from the triad, a seventh chord also includes the seventh, i.e., the seventh note of the scale.

A list of possible combinations of a seventh chord:

Major third + perfect fifth + major seventh = Major 7 chord (e.g., CMaj7)
Major third + perfect fifth + minor seventh = Dominant 7 chord (e.g., C7)
Minor third + perfect fifth + minor seventh = Minor 7 chord (e.g., Cm7)
Minor third + diminished fifth + minor seventh = Minor7b5 chord (e.g., Cm7b5)