Download The Common-Tone Diminished Seventh Chord 7

College-Conservatory of Music • University of Cincinnati • Instructor Paul Dell Aquila
The Common-Tone Diminished Seventh Chord
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The Common-Tone Diminished Seventh Chord
˜
The common-tone diminished seventh chord (ct 7 ) does not function as a typical diminished seventh sonority.
It is a chord of embellishment that usually progresses to a major triad
˜ or dominant seventh chord, the root of
˜
which is the same as one of the notes of the 7 chord. Although the ct 7 chord may embellish any triad or dominant
seventh˜ chord, it most often progresses to I or V7 in major (minor examples are rare).
The ct 7 chord may be spelled˜ in any manner as long as one of the notes be the same as the root of the chord it
embellishes. However, the ct 7 is usually spelled starting on the note an + 2 above the˜ chord it embellishes.
Exceptions to ˜this spelling can still be found in lead-sheet
notation. In general, the ct 7 that embellishes I is
˜
7
7
spelled as a # ii ˜ , and that which embellishes V as a # vi .
Because the ct 7 has no theoretical root no inversion figures are necessary for analysis. Also, because the chord
is a distinctly nonessential, embellishing chord that acts as a neighbor or passing sonority, the analytical symbol
is often˜ placed in parentheses.
The ct 7 chord is usually a˜ complete sonority
˜ but it may also be found in incomplete versions.
It is easy to confuse the vii 7/V with the ct 7 that embellishes the tonic because they are enharmonically equivalent
˜
and both chords are sometimes spelled enharmonically.
Keep the following in mind: If the chord following the 7
˜
˜
chord˜is I or I 6 it should be analyzed as ct 7. If the chord following the 7 chord is V or I 64 it should be analyzed
7
as vii /V.
Common-tone diminished seventh chords may also be used to embellish secondary dominants.
Mozart, Piano Sonata, K. 545, III
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College-Conservatory of Music • University of Cincinnati • Instructor Paul Dell Aquila
The Common-Tone Diminished Seventh Chord continued 2 of 2
Clara Wieck Schumann, Concert Variations, Op. 08, Var. 02
Tchaikovsky, Nutcracker Suite, “Waltz of the Flowers” (piano arrangement)
Sousa, “Semper Fidelis”
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