Three or more notes played at the same time form a chord. A chord consisting of exactly three notes is called a triad, which are typically made by combining two or more 3rds. For example, the notes C-E-G form the C major chord or C major triad. The note upon which the chord is founded (i.e. essentially the one the chord is named after) is called the root of the chord; so in the triad C-E-G, C would be the root. The other notes of a chord are named after the interval they form relative to the root (e.g. 3rd, 5th, etc).
As always, there is a little more to understand regarding triads. There are four different types:
- Augmented Triad: consists of a major 3rd and an augmented 5th
- Major Triad: consists of a major 3rd and a perfect 5th
- Minor Triad: consists of a minor 3rd and a perfect 5th
- Diminished Triad: consists of a minor 3rd and a diminished 5th
A chord is described as being in its root position when its root is the lowest note played. A three-note chord (a triad) can also be played in its first inversion or second inversion. A triad is in its first inversion when its 3rd (i.e. the second note; the E in C-E-G) is the lowest note played. A triad is in its second inversion when its 5th (i.e. the third note; the G in C-E-G) is the lowest note played. Naturally, the more notes a chord has the more Inversions there are to play.
|Degree||Major||Natural Minor||Harmonic Minor||Melodic Minor|
Many people have heard of 7th chords, particularly if you ever played guitar, but very few actually know what they are. Essentially, if you add another 3rd to any chord, you get a 7th chord. It is called such because a 7th interval is formed in relation to the root, and a 7th chord can be built on any degree of a major or minor scale. There are five different named types of 7th chord, which are defined by the triad and the 7th interval forming the chord:
- Major 7th Chord: consists of a major triad and a major 7th
- Dominant 7th Chord: consists of a major triad and a minor 7th
- Minor 7th Chord: consists of a minor triad and a minor 7th
- Half-diminished 7th Chord: consists of a diminished triad and a minor 7th
- Diminished 7th Chord: consists of a diminished triad and a diminished 7th
We could list all the 7th chords, how they are formed and on which degrees of the major and minor scales; but, frankly, there is no point because it gets so complicated that we start listing chords that don't even have names. That is a pretty good indication that we have covered enough.