Chord Progressions & Harmonic Analysis

In tonal music, the relationship between successive chords (vertical sonorities) is called chord progression (or harmonic progression). Each chord in a progression is related to the others by its root.

We can do an harmonic analysis of a piece of music by examining its chord progressions and then labeling each chord as to its function within a given key (tonal center). This analysis can help us to understand the music better, and if we understand the music better, we can give the music a better performance.

First we must determine the key (major or minor) of the music. Then we can examine each chord for type and inversion, if any. To do this, we use Roman numerals to indicate the root of each chord. This will show the function of each chord within the given key. Then we add Arabic numerals (as super scripts along side the Roman numerals) to indicate chord inversions, if any, and to show any added note chords present (such as 7th, 9ths, etc.).

It is conventional in this type of analysis to use upper case Roman numerals for major and augmented chords and lower case Roman numerals for minor and diminished chords. And since there are only seven different tones in a major or minor scale, we need use only the first seven Roman numerals to indicate the chords built upon these tones (ex.1).

Harmonic rhythm is the rate at which the chords change in a piece of music. The harmonic rhythm can be fast (changing more than once per beat), moderate (changing each beat or each measure) or slow (changing every other measure or less often).

When a composer combines a melody with chords it is called harmonization. This is usually done by simply adding chords to an existing melody. But it can also be done by deriving a melody from a chord progression.

The notes in a melody may contain any combination of chord tones and non-chord tones. All chord tones are consonant (needing no resolution). All non-chord tones are dissonant (until resolved to a chord tone). However, if all the tones in a melody were chord tones only, the music would be rather simple and uninteresting. To that end, composers use many non-chord tones to enhance their melodies and make them more appealing. Dissonant tones and their resolutions also tend to give the music a sense of movement.

A neighbor tone (N) is a tone that leaves and then returns to the same chord tone by step, either from above (upper neighbor) or from below (lower neighbor) (ex.3).

A leaning tone (appogiatura) (L) is a tone which leaves a chord tone by skip and then returns to another chord tone by step in the opposite direction (ex.4).

An anticipation (A) is a tone which leaves a chord by step (as a dissonance) and then is repeated in the following chord (as a consonance). Anticipations are always before the beat and unaccented (ex.6).

A suspension (S) is a three step process involving preparation, suspension and resolution. A chord tone in one chord (preparation)(consonance) is tied over to the next chord (as a suspension) (dissonance) before changing to a chord tone again (resolution) (consonance) (ex.7).

When doing an harmonic analysis, we must first determine the key of the music. To do this, first look at the key signature, then at the first and last notes of the piece (or section) and then at the content in general. It should soon become clear (if the music is not too chromatic) what basic key is being used. This of course requires a good knowledge of both major and minor scales and their respective key signatures.

Hint: To find the root of a three note chord, look for the top note of a fourth. To find the root of a four note chord (seventh), look for the top note of a second.

To determine a particular chord, you must take into account the vertical sonority at a particular point. It's best to start at the beat level and work measure by measure. Remember that some chords may change at a rapid pace while others may change more slowly.

A good method for determining a chord is to look at all the tones in a measure. Then reduce the tones, beat-by-beat, to the smallest number of different tones possible (remember that repeated notes and octaves are counted as the same). Try to determine which notes are chord tones and which are non-chord tones. Then stack these chord tones up vertically in thirds to see what chords they resemble (refer to the scales and triads you constructed as needed). Keep in mind that the chords might be in an inversion, however, this does not change the basic chord quality.

After you determine a chord, label it using the appropriate Roman numeral. Remember to use upper case Roman numerals for major and augmented chords and lower case Roman numerals for minor and diminished chords. Be sure to place the Roman numeral for each chord directly under the chord and just below the staff.

Once you gain some skill and confidence in determining and labeling the basic chord structure, you can go back and try to determine the chord inversions, if any. This will require the use of Arabic numerals which need to be placed as superscripts along side of each Roman numeral.

In three note chords, a first inversion is indicated by adding the numeral 6, and a second inversion is indicated by adding a numeral 6 above a numeral 4 (to look like a fraction). These numerals indicate specific intervals above the bass note of a chord.

In four note chords (7ths), a first inversion is indicated by adding a numeral 6 above a numeral 5, a second inversion is indicated by adding a numeral 4 above a numeral 3, and a third inversion is indicated by adding a numeral 4 above a numeral 2. Again, these numerals indicate specific intervals avove the bass note of a chord (ex.9).

When doing an analysis of a piece of music, we can be confronted with a wide variety of musical textures. The three basic kinds of textures found in most music are: 1) monophonic (one melody alone), 2) homophonic (one melody with accompaniment) and 3) polyphonic (two or more melodies sounded simultaneously).

For the purposes of this introduction to harmonic analysis, we will consider only various examples of homophonic texture. Within homophonic texture there can be many different types of accompaniments such as block chord, sustained chord, repeated chord, broken chord, beat and afterbeat and mixed accompaniments (any combination of the above). When first attempting harmonic analysis, it is best to start out with the simpler textures of block chords and sustained chords.

Identify and label all non-chord tones in this chorale melody by Bach (ex.10). Place the appropriate letter (P, N, L, E, or A) above each non-chord tone. The chord symbols below the staff indicate the underlying harmonic rhythm.

Identify the quality of each chord in this complete 4-part chorale by Bach (ex.11) by placing the appropriate letter of the alphabet underneath each chord. This will show the quality of each chord but not function. Hint: The basic harmonic rhythm changes every quarter note. (Leave blank any chords you can't identify.)

For this assignment disregard chord inversions and remember to use upper case letters for major and augmented chords and lower case letters for minor and diminished chords.

Identify the function of each chord in this complete 4-part chorale by Bach (ex.11) by placing the appropriate Roman numeral under each chord. (You may add these symbols directly below the letters of the previous assignment if you like.) This will show the function of each chord within the key of F major. Hint: The basic harmonic rhythm changes every quarter note. (Leave blank any chords you can't identify.)

For this assignment disregard chord inversions and remember to use upper case Roman numerals for major and augmented chords and lower case Roman numerals for minor and diminished chords.

Identify all chord inversions in this complete 4-part chorale by Bach (ex.11) by placing the appropriate Arabic numerals (written as superscripts) beside each Roman numeral of the previous assignment.

Remember that in three note chords, a first inversion will have the third in the bass (6), and a second inversion will have the fifth in the bass (6/4). In four note chords (seventh chords), a first inversion will have the third in the bass (6/5), a second inversion will have the fifth in the bass (4/3) and a third inversion will have the seventh in the bass (4/2).

In this complete 4-part chorale by Bach (ex.11) there are at least three instances of suspensions. See if you can locate them. Label these suspensions by writing P (preparation), S (suspension) and R (resolution) over the proper tones. Hint: The suspensions are between tones of the soprano and alto or the alto and tenor.