Four Basic Types of Chords
In general, chords are built by starting on a note and taking every other note from there. The basic chords are three notes, and can be major, minor, diminished, or augmented. The fact that you skip notes means that chords have a root note, a third, and a fifth. What kind of chord you have depends upon the type of third and the type of fifth. I wrote about intervals in a previous article.
A major chord has a major third and a perfect fifth. An easy example is C - E - G.
A minor chord has a minor third and a perfect fifth. In other words, it’s just like a major chord except that you drop the middle note a half step. D - F - A is a D minor chord.
A diminished chord has a minor third and a diminished fifth. B - D - F is a B diminished chord.
An augmented chord has a major third and an augmented fifth. F - A - C# is an F augmented chord.
Once you know what chord you have, it’s easy to convert to another type of chord. To make a major chord into a minor chord, keep the fifth the same but lower the third by a half-step. For example, E - G# - B is an E major chord. To make it an E minor chord, change the G# to a G: E - G - B is E minor.
Make a minor chord into a diminished chord by lowering the fifth. E - G - Bb is an E diminished chord.
Make a major chord into an augmented chord by raising the fifth. E - G# - B is E major, so E - G# - B# is an E augmented. (Note that we use the notation B# for the same sound as C…the reason is that it shows we’re talking about the fifth of the chord).
In the next article I’ll tell you my system for quickly figuring out what notes go into any chord.