Harmonic Analysis - Full Diatonic

Harmonic Analysis - Full Diatonic…

Key Signatures

A Key Signature is a summary of the sharps, flats and natural notes used in a section of music. Traditional key signatures represent major and their relative minor keys. A key signature can represent any scale or mode.

The Key Signature can sometimes be used to determine the starting tonality. More often the last chord of a progression will most likely be the tonic or I chord and the main or central tonality. Even if the tonality can not be determined a harmonic analysis can be started.

Start by determining the first tonal center using the clues (key signature and or last chord or note). Now find its harmonized chord chart. The most common tonality is major comprising of a large majority of contemporary music.

Start assigning roman numerals to the basic chords of the progression. Ignore single beat chords, the upper partials of chords such as ninths, elevenths, and thirteenths. Ignore alterations such as flat and sharp nines and sharp elevenths.

Familiarize yourself with both the basic triads and 4-part chords types on the Harmonized Chord Chart(s) for the Major Keys. (Review the Harmonic Analysis - Basic Concepts lessons of this series for the C Major scale chords.

4-Part Chords

Triads

Note: For Harmonic Analysis purposes a triad and 4-part chord serve the same harmonic function.

EXAMPLE 1

Starting with this simple, very common chord progression and the Harmonized Chord Chart(s) we'll take each chord one at time.

The first chord, a Dm7 is in both the major and minor charts. In a major tonality it’s a II chord in the key of C, a III chord in the key of Bb and a VI chord in the key of F. In a minor tonality it’s a I chord in the key of D minor and a IV chord in the key of A minor – 5 choices.

The second chord, G7 is found in both the major and minor charts but only as a V chord in the key of C Major or C Minor. Store this information away for future reference – 2 choices.

The Cmaj7 chord is a I chord in the key of C major and the IV chord in the key of G major. In a minor tonality it's as a III chord in key of A minor and a VI chord in the key of E minor – 4 choices.

Here are the possibilities we now have using the Major and Minor Harmonized Chord charts:

We can rule out numbers 1 and 2 as at least one of the chords do not show up in the major or minor harmonized scale chart.

We can then rule out numbers 4 and 5 as they do not have I or tonic chords. This leaves number three as the best choice. This is one of the most common progressions used in contemporary music. You will see this progression more than any other progression, especially in jazz standards.

Using uppercase roman numerals place a II under the Dm7, a V under the G7 and a I under the Cmaj7. To indicate the key place an uppercase letter before the II with a colon following the letter to indicate the tonal center.

The same analysis would result if the chords where basic triads: Dm, G, or C

Song and Chord Progression Examples

Lots of folk and children's songs as well as many rock and popular songs contain full diatonic progressions or sections and are a good place to practice your RMA.

Here are a few examples of jazz songs with full diatonic progressions. Many songs contain full diatonic sections. Full diatonic is the most common harmonic principle.