We're going to build chords out of notes in a specific key - the key of C Major - but the formula applies to any key. The first thing to understand is the "triad." First, lets review a one-octave scale in the key of C Major:
C - D - E - F - G - A - B - C
Chords begin life as triads and a triad is just what the name implies - a grouping of three notes. Triads are built from the bottom up (although the notes can be grouped in other ways, called inversions) in the beginning. It works like this. Start with the first note in the key (C), then count to the third note and put that on top of the C (E), then count to the fifth note above C and put that on top of the E (G). Here is how that "stack" of notes looks:
Now you need to do the same thing with each note up to and including the seventh note in the scale. Here's how they "stack up":
G A B C D E F
E F G A B C D
C D E F G A B
Remember, you're starting with each note in the key of C Major and on top of each note you're putting the third and the fifth note above each. What you now have - although you don't know it yet! - are a series of chords.
Wait a minute, you say. When I play a chord on the guitar it has more than three notes! And you are correct, in almost all cases, in common 1st position chords anyway. Hold that thought for the moment!
The reality is this: all Major, minor, diminished and augmented chords - the basic building blocks to which we add other notes to make ALL OTHER CHORDS, have a minimum of three notes. They are called the root (that first note you started with in each "stack"); the third (that third note above each root); and the fifth (the fifth note above the root). In the case of the first one we made above, it goes like this:
Every complete Major, minor, diminished or augmented chord has a root, third and fifth. And here's the most important fact: the musical distance between those three notes determines whether a chord is Major, minor, diminished or augmented.
Please stop for a second and re-read that last paragraph. Accept it at face value for now, but burn it into your memory!
OK, that's all for now. Stay with me - this will all become clearer as it relates to what you know how to play in the near future! (I won't be able to post for a few days, but check back next week for Part 4!)
Peace & good music,