MUSIC THEORY

Mod 16

• Subject of the Day: Chord Inversion Symbols
• Reading Assignment: Kostka, pp. 44-48
• Written Assignment: Workbook, Ex. 3-3 (Leave blank the chord type for all 7th chords)
• Semester Schedule

Seventh Chords
Extending a triad by adding another third on top results in a seventh chord.  It gets it name from the fact that the interval from the root to this added note is a seventh.  In seventh chords there are four members (root, third, fifth, and seventh).  The most common seventh chord is that which is built on the dominant (5th scale tone) of a key.  This is a major triad with a m7 from its root to the seventh and is commonly called a dominant seventh.
 
 

In order to do an harmonic analysis it is necesarry to recognize chords in inversion.  To do this, one must take the three or four notes of the chord and (by trial and error) determine which note will be on the bottom when stacked in thirds  (A C E G B D F A C E G  etc.).   This bottom note is the root of the chord.  With the root in the lowest position the chord is said to be in root position.   With the third of the chord  in the lowest position the chord is said to be in first inversion.   With the fifth in the lowest position it is called second inversion.   With the seventh in the lowest position we say that the chord is in third inversion.   (Of course, only seventh chords can have a third inversion)  Spacing of the upper notes in a chord does not affect the chord position, only the lowest note does.
 
 

The symbols used for these inversions are as follows:

Triads:    No symbol or a 5 or 5 indicates a root position triad
                                                3

                6  or  6  indicates a first inversion triad
                3

                6  indicates a second inversion triad
                4

Seventh Chords:     7  indicates a root position seventh chord

                                 6  indicates a first inversion seventh chord
                                 5

                                 4  indicates a second inversion seventh chord
                                 3

                                 4 indicates a third inversion seventh chord
                                 2

If you still have questions, contact Dr. Bartolotta at wbartolo@odu.edu