When beginners learn chords on the guitar, they soon realize they are being instructed to play all 6 strings on some chords, only 5 on a few others, and in the case of D, only 4.
This is because these chords are all in what is referred to as root position. The simplest way to understand this at first is to see that the lowest note played in each chord is the same as the name of the chord itself.
For example, the lowest note played in the E major chord is the open 6th string E, and the lowest note played in A minor chord is the open 5th string A. If the lowest note played is a fretted note, it still is the root—the lowest note played in the C chord is C at the 5th string, 3rd fret. For the C chord, the sixth string is not played. The corresponding chord box for C will show the 6th string has an X, instead of O for open.
So it is that in these chords, 4, 5 or even 6 strings are played. However, there are only 3 notes in each of these chords. Some of the notes may be doubled, or even tripled, but every major and minor chord has 3 notes only. They are made from the major scale they are the first note of.
1 2 3 4 5 6 7 8
Example: C D E F G A B C C major scale
1 3 5
C E G C major chord
The major chord is made from the 1st, 3rd and 5 notes of the C major scale.
The minor chord is identical to the major chord except the 3rd is flatted, or lowered ½ step:
1 2 3 4 5 6 7 8
C D E F G A B C C major scale
1 b3 5
C Eb G C minor chord
The major and minor chords are also referred to as triads. All chords come from one of 4 triad types. The following page describes each one in detail. For now, familiarize yourself with the construction and most of all the SOUND of the major and minor chord. In western music, we are conditioned to hear the major chord as brighter, happier, etc, and minor chord darker, sadder, etc. One of the best and most basic aspects of training the ear is to hear the difference between these two chord types.
©2012 Jim Greenfield