There are several different types of chords. But the two most common types of chords are major chords and minor chords. What we need to learn here is the difference in sound between the major chord and the minor chord. This is the major chord [David plays chord of D major] and this is the minor chord [David plays chord of D minor]. You will notice that the minor chord sounds melancholy compared to the major chord. [David plays chord of D major again] and then the minor chord [David plays chord of D minor again].