MUS 111 Study Guide I (Chapter 9)
The Triad in Inversion
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Inverting a chord simply means placing a chord
member other than the root as the lowest sounding voice. The
exclusive use of root position chords is not common. Use of
inversion has two advantages–one harmonic and the other melodic.
The triad in first inversion:
Harmonic advantage: A triad and its inversions
provide three different sonorities while using the same letter names–four
for seventh chords. Inversions provide an interesting harmonic
change. The easiest way to introduce an inversion is by
arpeggiating the bass line.
Melodic advantage: Without inversions, the
lowest voice lacks any sense of being a melodic line. With
inversions, scale steps can be introduced and the bass can truly
become melodic. In a series of first inversions in which the
bass moves stepwise, any chord progression may appear, even those that
are uncommon. The use of the progression V-IV is limited, but in
a succession of first inversions its use is common.
Inversions can create musical interest by: (a)
arpeggiating a triad, (b) progressing by leap from triad root to
inversion, or from inversion to inversion, (c) using a scale line in
the bass, where the inversion is found intermittently, or when
inversions are in succession, (d) moving the bass line in thirds or
sixths with an upper voice.
The triad in second inversion:
In contrast to the liberal use of first inversions,
the second inversion is restricted to a limited number of specific
devices. (This is due to the fact that second inversion creates
a P4 between the bass and one of the upper voices, which was
considered a dissonance in the early days, and requires a specific
resolution. In essence, it is an unstable chord.)
The Cadential Six-Four Chord: so-named
because of its frequency of use at a cadence point, though it
appears in other locations. Harmonic movement culminating in a
I 6/4-V-I cadence is so common that the progression is virtually a
"trademark" of tonal harmony. In essence, the I 6/4
chord functions as a V chord with two nonharmonic tones above the
"root." The "root," of course, is the dominant scale degree.
It is still analyzed as a I 6/4 chord. The chord
"resolves" to the V chord at the cadence. Used in
this manner, the 6/4 chord is a decoration of the V chord–with the
"6" and "4" of the I 6/4 resolving to
"5" and "3" of the V chord. The bass note
is doubled. (See later example.) [Note:
"6/4" is the easiest way to indicate a second inversion
symbol here on the web ... See actual music example, later,
too see how it "really" looks. ;-)]
The Passing Six-Four Chord: The bass
note (5th factor) of the 6/4 acts as a passing
tone. The passing bass may be found as a tonic 6/4 between the
IV and IV6 chords, or as a dominant 6/4 between the I and
I6 chords. The bass note is doubled. (See later
The Arpeggiated Bass Six-Four Chord:
The bass note (5th factor) participates in an
arpeggiation of the same chord. The usage of 6/4 chords occurs
occasionally with triads other than the tonic. The bass note
is doubled. (See later example.)
The Pedal Bass Six-Four Chord: Also
known as static bass or neighboring tone chords, the
bass note (5th factor) is preceded and followed by the
same tone and is interspersed between two root positions of the same
triad. This type also occurs occasionally with the IV 6/4 as
well as the tonic. The bass note is doubled. (See later
Note: The bass note is doubled in all 6-4
types. Also, a general rule is the bass of a 6-4 chord must be
prepared either by step or repetition and must resolve by step or
repetition. The exception is the arpeggiated bass.
Writing a Triad in First Inversion: With major triads the soprano
note is usually doubled. Although, any chord factor which facilitates
smooth voice-leading is acceptable. With minor triads the same
guideline applies, however, doubling the third is also common.
Writing to or from a Triad in First Inversion:
It is easiest to
first write the two voices that lead to and from the doubled note.
These two voices can move in three different ways in relation to each
Contrary motion: the two voices move in opposite directions.
Oblique motion: one voice remains stationary while the other
Similar motion: the two voices move in the same direction.
It is always best to use contrary or oblique motion in
approaching and leaving the doubled note. Similar motion is usually
only necessary in cases when one voice must be brought into a better
range or to effect a change in position.
- The most efficient procedure for part-writing to or from a triad in
first inversion is as follows:
Complete the first of the two triads.
Approach or resolve the doubled note by contrary or oblique
motion if possible.
Fill in the remaining voice with the note necessary to produce
normal doubling. When the doubled note moves by contrary or oblique
motion, the remaining voice usually moves by step or remains
stationary, rarely moving by leap.
- Writing Successive Triads in First Inversion: When triads in first
inversion are used in succession, it is impossible for each of these
triads to be found with the usual doubling in the same pair of voices,
since parallel octaves and fifths will result. To avoid these, use a
different doubling for each triad, if necessary. When selecting
doublings, be sure not to double the leading tone or any altered tone.
- Writing a Triad in Second Inversion: The fifth (bass note) is
ordinarily doubled. Approach and resolution:
Cadential: The bass note is not approached from the
same tone or from the leading tone. As stated earlier, scale degree
6 moves to 5 above the bass, and 4 moves to 3.
Pedal: Motion above the bass is usually stepwise.
Passing: The "dissonant" fourth remains stationary.
Other Part-Writing Considerations:
The Melodic Augmented Fourth: should be avoided.
tones of the interval have strong resolution tendencies–the upper
resolving up and the lower resolving down. In a melodic leap, both
resolutions cannot be accommodated, and the undesirable large leap
must continue in the same direction. The problem is easily resolved
by using the A4's inversion, the diminished fifth (d5), thus
allowing melodic change of direction.
Overlapping Voices: occurs between two chords when one
voice moves above or below the previous pitch of an adjacent voice.
Overlap should be avoided; however, if necessary, do not overlap two
adjacent voices more than a whole step. Correction is sometimes as
simple as changing the direction of one voice. Otherwise, change the
triad position at some point before the overlapping pair.
Hidden Octaves and Hidden Fifths: (also called
Direct Octaves and Direct Fifths) A hidden octave occurs when two
voices progress in similar motion to a perfect octave ... ditto for
the hidden fifth. Although not parallel, they often produce the
aural effect of parallel movement. These two motions are a problem only
when they occur between the two outside voices (soprano and bass).
They are acceptable under the following two circumstances: (1) when
the soprano moves by step, as in the P.A. cadence, soprano scale
steps 2-1 with bass descending, and, (2) when the bass moves by the
interval of an octave–considered the same as a repeated tone.
other circumstances, a hidden fifth or octave between outside voices
is not necessarily unusable, but should be a last resort.
- Melody Harmonization: When harmonizing a melody using inversions,
you must decide which triads will be in inversion and which will be in
root position. That said, you should write the complete bass line
first. When the bass moves with the soprano, their related movements
can be in any one of four directions:
Contrary motion to each other.
Oblique motion–soprano stays on the same tone while the
bass moves, or vice versa.
Similar motion to each other.
Stationary motion–both soprano and bass repeat their
Again, contrary and oblique motion are used most often. Similar
motion is effective for intervals of thirds or sixths between
soprano and bass, but otherwise should be used with care, avoiding
parallel or hidden octaves and fifths.
As a final test of the chosen bass line, play it with the
soprano. The two lines alone should be musically effective, even without the
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