A Structural Examination of Tonality, Vocabulary, Texture,
Sonorities, and Time Organization in Western Art Music



Chapter 16. Second Inversion Triads

Chapter 15. Connections
Chapter 17. Phrase Design


Triads in root position and 1st inversion are common, but 2nd inversion triads are problematic. Any triad may be voiced in the 2nd inversion, but the resulting sonority is extremely unstable, due to the dissonance of a 4th above the bass.

There are four types of 2nd inversion triads (commonly called 6/4 chords) that can be found in the Common Practice Period:

  1. Cadential 6/4
  2. Arpeggiated 6/4
  3. Passing 6/4
  4. Pedal 6/4

All second inversion triads MUST have an explanation/justification for their presence in the music. This requires that a label be attached to the Roman numeral.


Composers frequently prolong the arrival of dominant at a cadence in order to increase harmonic tension. This is frequently done with the insertion of a CADENTIAL 6/4. In spite of the fact that this chord resembles tonic (containing ^1 - ^3 - ^5), in reality it has nothing in common with the tonic function to the ear. It does not provide stability and, in fact, has a strong need to resolve to dominant.

Since ^5 is in the bass, the cadential 6/4 proves to be an expansion of dominant and cannot be separated from it. It is inappropriate to label it with the tonic Roman numeral. Instead, it is written with the dominant numeral plus figured bass symbols above it.

This particular sonority is commonly found in all music of the Common Practice Period, and is an extremely effective means of defining a cadence. The cadential 6/4 actually becomes part of the cadence, with a single Roman numeral to define both the 6/4 and the dominant that follows. It is so common and so effective that it could be labelled as a Super Perfect Authentic Cadence.

Notice the voice leading typically found:

Although the cadential 6/4 is minor in minor keys, it is still written with the uppercase Roman numeral since it is an expansion of dominant and the dominant function must always be major (minor dominant will be discussed in Chapter 19).

There are five characteristics which define the cadential 6/4:

  1. It must contain ^1, ^3, and ^5 (and no others)
  2. It must have ^5 in the bass
  3. It must prolong the arrival of dominant, so it cannot cannot be preceded by any form of dominance
  4. It must move to dominant (or some form of it)
  5. It must be in a rhythmically stronger place than the following dominant

The cadential 6/4 (with a following dominant and tonic) supports a ^3 - ^2 - ^1 motion (Mi - Re - Do) or a ^1 - ^7 - ^1 motion (Do - Ti - Do) in the soprano. supported by ^5 - ^5 - ^1 (Sol - Sol - Do) in the bass. The cadential 6/4 is the most important type, and the most often found, second inversion triad.

The cadential 6/4 is not restricted to just cadences. This particular sonority is readily found in subordinate progressions as well.

The force that binds the cadential 6/4 to its following dominant is powerful. CONCERTOS from this period frequently contain CADENZAS (extended passages in which the soloist performs alone, without any accompaniment). It is traditional for these cadenzas to begin after the establishment of a cadential 6/4, and to end with a dominant 7. No matter how long the cadenza is, whether it is a few seconds or many minutes, the need for the ear to hear the cadential 6/4 resolve to dominant never fades.


The arpeggiated 6/4 is the result of a bass line leaping (or arpeggiating), forming different positions of the same harmonic area. The arpeggiated 6/4 is always next to a more stable form of the same Roman numeral.

Since Roman numerals should be labelled by its lowest most stable position, arpeggiated 6/4's do not receive a label in harmonic analysis.

In the example above, positions of tonic are given inside the parentheses. They are not necessary for the Roman numeral analysis since root position tonic is clearly the main event.

16.4 THE PASSING 6/4

The passing 6/4 is the result of a specific passing motion in the bass, either up or down. In the example below, the ^2 is supporting a dominant triad in second inversion. The passing 6/4, like any passing chord, is a prolonging gesture, so it passes between two chords of the same or similar function.

Note that the dominant triad in second inversion must receive a "passing" label (P). If a structural analysis is included, the label appears there.

16.5 THE PEDAL 6/4

The pedal 6/4 is the result of a stationary bass line. In the example below, the middle ^1 is supporting a subdominant in second inversion. The pedal 6/4 is a prolonging gesture, and it will return to the same or similar function that it begins with.

Note that the subdominant triad in second inversion must receive a "pedal" label (ped).If a structural analysis is included, the label appears there.


It is possible to find the three scales degrees that form tonic (^1 - ^3 - ^5) as sonorities in a phrase which require substantially different explanations each time. It is important to recognize the differences and label them correctly, as in the example below.

Learn more about inversions


Tonic, dominant (7), supertonic (7), subdominant in several positions, leading tone in first inversion, and all the 6/4 types [new items in red]

Major keys

Minor keys



Provide a Roman numeral and structural analysis, and circle and label all non-chord tones, for the following pieces in Music for Analysis:

  1. Chopin: Mazurka, op.24, no.3 [#36] Listen to a performance
  2. Beethoven: Trio, op.97 [#38]
  3. Beethoven: Six Variations on "Nel cor piu non mi sento" [#52, CD track #7]
  4. Haydn: Trio in C Major, Hob. XV: 3 [#65]
  5. Beethoven: Concerto No. 1 for Piano, op.15 [#69] Listen to a performance
  6. Mozart: Rondo, K.485 [#71, CD track #9]
  7. Beethoven: Sonatina in G Major [#76, CD track #9]
  8. Haydn: Sonata in D Major, Hob. XVI: 37 [#79, CD track #9] Listen to a performance


Add soprano, alto, and tenor lines to this figured bass, and include, with eighth notes only, at least 4 passing tones (never more than one in any given beat) in the upper three voices. Circle and label the non-chord tones and provide a Roman numeral and structural analysis:

To prepare this writing assignment properly, use the notation guidelines appendix, located at Basic Principles of Music Notation, Semester II.

Links to chapters in this unit:
Chapter 15. Connections
Chapter 17. Phrase Design

Link to previous unit: DIATONIC PROCEDURES I: Harmonic Dimensions

Link to next unit: DIATONIC PROCEDURES III: Substitutions

Copyright 2008-2009 by Phillip Magnuson.

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