Lesson GGG: Seventh Chords Introduction: Seventh chords provide an additional range of sonorities to the tonal landscape. Because they contain four distinct pitches and include a dissonance by default, they lend richer, fuller harmonies than their triadic counterparts. It is this very dissonance, however, that makes the treatment of seventh chords a delicate matter.
In this lesson you will first learn about the various categories of seventh chords and become familiar with their construction. Following this, there will be a more specific discussion that will touch on the commonly used seventh chords and why other seventh chords are not used. (Seventh chords are also frequently used as auxiliary sonorities. For more information on auxiliary sonorities, refer to Lesson CCC.)