The Four Basic Types of Chords
Major, Minor, Diminished, and Augmented Triads
Chords are constructed of at least three different letter names. The most basic kind of chord is called a triad. A triad uses only three different letter names.
The notes of a chord are called "members". The members of a c major chord are the notes c, e, and g. CONFUSING FACT: Chords are by definition made of three or more different letter names. An exception to this rule - a power chord - has only two different letter names.
There are four different kinds of triads: major, minor, diminished, and augmented. Each type has a slightly different construction.
In music we have two different ways of measuring distances, half steps (frets) and intervals (letter names/lines and spaces). Chords are usually built using intervals called thirds. Intervals are named by counting letter names (or lines and spaces on the staff). Unfortunately all letter names are not the same number of half steps apart, so we must also count half steps. For example, the number of half steps from B to C is one, while there are two half steps from C to D. Check out these examples using a piano keyboard and a guitar fretboard.
Since triads are built of thirds - one type of measurement - we can distinguish between different kinds of triads by counting half steps - the second method of measuring distances. With both of these measurement tools in our tool box, we can now differentiate between the four different kinds of triads.
