IV. Diatonic Harmony, Tonicization, and Modulation
6/4 Chords as Forms of Prolongation
John Peterson
Key Takeaways
This chapter introduces three additional
- Passing (pass.)
involves a passing tone in the bass that has been harmonized by a chord. It typically prolongs tonic or predominant harmonies, and it always occurs between two chords of the same function. - Neighbor (n.)
involves a static bass above which two of the upper voices perform upper neighbor motion. It typically prolongs tonic or dominant harmonies, and the chords on both sides of it are always in root position. - Arpeggiating (arp.)
involves a bass that arpeggiates through the fifth of the chord while the upper voices sustain the chord in some way. It may prolong any harmony, and we don’t typically bother recognizing it in analysis.
The table in Example 6 below summarizes the characteristics of each of the three types of
So far, we’ve seen that the tonic (T) area is most commonly prolonged using dominant-function chords, especially inverted
Passing
The passing (pass.)
Example 1.
Example 2a demonstrates the steps for writing
To write with pass :
- Write the entire bass. You should have three notes in stepwise motion where the first and last notes belong to the same functional area (T or PD). The middle note will be your passing tone.
- Spell the pass.
. Just like with , to spell , determine what notes are a fourth and sixth above the bass. One voice will double the bass, just like in . - Write the entire soprano. The soprano should be a line that moves by step, not the static line.
- Fill in inner voices, making them move as little as possible.
Example 2. Writing with pass.
Neighbor
The neighbor (n.)
Example 3. Neighbor and arpeggiating
To write with :
- Write the entire bass. The bass will be three of the same note, typically do–do–do or sol–sol–sol (
or ) - Spell n.
. The will be over the middle bass note. As with and , determine a sixth and fourth above the middle bass note. One voice will double the bass. - Write the entire soprano. For the soprano, choose either an upper-neighbor line or the static line. Unlike with
or , will more frequently have a static line in the soprano. - Fill in the inner voices, making them move as little as possible.
Example 4. Writing with
Arpeggiating
Arpeggiating (arp.)
Example 5. Arpeggiating
Summary: 6/4 chord types
The table in Example 6 summarizes the characteristics of the three
[table id=45 /]
Example 6. Summary of
chords as forms of prolongation (.pdf, .docx). Asks students to review previous concepts, write from Roman numerals, write from figures, and analyze excerpts.
A type of motion where a chord tone moves by step to another tone, then resolves by step in the same direction. For example, C–D–E above a C major chord would be an example of neighboring motion, in which D can be described as a passing tone. Entire harmonies may be said to be passing when embellishing another harmony, when the voice-leading between the two chords involves mainly passing tones (as in the passing 6/4 chord).
A type of motion where a chord tone moves by step to another tone, then moves back to the original chord tone. For example, C–D–C above a C major chord would be an example of neighboring motion, in which D can be described as a neighbor tone. Entire harmonies may be said to be neighboring when embellishing another harmony, when the voice-leading between the two chords involves only neighboring and common-tone motion (as in the common-tone diminished seventh chord).
A melodic, "horizontal" statement of a triadic harmony; in other words, each note of a triadic harmony played in succession (rather than simultaneously). Also referred to as a "broken chord."
A common embellishment of the cadential V chord, in which the fifth of the V chord (re, 2̂) is replaced with the sixth (mi/me, 3̂) and the third (ti, 7̂) is replaced with the fourth (do, 1̂). The sixth and fourth form a 6/4 chord, hence its label. The cadential 6/4 resembles a I6/4 in its pitch content.
A 6/4 chord built on a passing tone in the bass, most commonly found prolonging tonic or predominant harmonies. Importantly, the chords on both sides of the passing 6/4 are always the same function.
A kind of 6/4 chord that embellishes a harmony with neighbor motion. This is usually labeled with figures, e.g., with 5-6-5 in one voice and 3-4-3 in another.
A 6/4 chord that results from an arpeggiated bass line (e.g., if the bass line alternates between the root and fifth of the same chord).