Division of Music | Dr. Patrick Houlihan | email:.houlihanp@alpha.obu.edu

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Class Notes: Chapter 10  
 

Introduction 

Syllabus  

UNIT TWO: NINETEENTH-CENTURY CHROMATIC PRACTICES 

Compare 18th and 19th centuries 
Text p149 
Text p262 
Harmonic Contrast: More chromaticism--most of the Haydn accidentals indicate a new key, not chromaticism. 

Discuss 19th century: 
Other differences between Classical and 19th cent: 
Expansion of forms: lengths of operas, symphonies, concerti; new themes introduced in development and coda of sonata form. 
More contrapuntal writing. 
Blurring of harmony; longer, stronger nonharmonic tones. 
More frequent modulations. 
Avoiding dominant-to-tonic cadences. 
Avoiding clear definition of tonal center at the beginning of a mvt. 

Chapter 10: Enharmonic Use of Chords 

Review Augmented Sixth  

Workbook p75: number 7 

In 18th century, augmented 6th chords were rarely used in major keys. 19th century: increasing use of augmented 6th chords in major keys. 

The Doubly Augmented Fourth Chord 

Write a German augmented 6th in B-flat major in four parts and resolve it to a tonic six-four chord. 

As it resolves to the tonic six-four, there's a problem: D-flat moves to D-natural. 

Composers increasingly used an enharmonic spelling of the German augmented 6th to solve this problem. Change the D-flat to C-sharp, which is enharmonic. This note is a doubly augmented fourth above the bass. 

See text p196, Schumann ex. 

Drill: WB p76 B #10. 

Doubly Augmented Fourth Reminders: 

1. Only in major mode.
2. Only when followed by the tonic six-four chord.
3. Same voice leading as the Gr+6.

Gr+6 as Enharmonic Pivot (pp198-204) 
Gr+6 is enharmonic to a dominant 7th chord. Any V7 or secondary V7 can be reinterpreted as a Gr+6. See the text's examples: Ill. 10.5a and 10.5b on p. 198. As in both of these examples, the chord is spelled properly for the new key (the V7 in ex. a; the Gr+6 in ex. b). 

In the major mode, the doubly augmented fourth chord may be used instead of the Gr+6. 

The It+6 is enharmonic to a dominant 7th chord with the fifth omitted. This can also be used as an enharmonic pivot, but it is less common than the Gr+6. 

Gr+6 as Enharmonic Pivot (cont.)

Note errors in text:

1. p200 ex. b
2. p201 V7/IV

What you need to be able to do:

1. analyze
2. write examples from Romans or fig bass.

Practice: WB p47 mm15.2–16.4. Begins in f mi.

Enharmonic Diminished 7th Chord

A diminished 7th chord can be enharmonically spelled four different ways.

1. Write a G diminished 7th chord in root position.
2. Next, write an E diminished 7th chord in first inversion. Notice that it is enharmonic to the G diminished 7th chord.
3. Write an A-sharp diminished 7th chord and a C-sharp diminished 7th chord, both with G in the bass. These two chords are also enharmonic to the G and E diminished 7th chords.

Because these chords are enharmonic, they can be used as enharmonic pivot chords. For example, to modulate from b minor to d minor, you could use the vii°7 (A-sharp diminished 7th) and respell it as a first-inversion vii°7 in d minor (C-sharp diminished 7th). See the Beethoven example on p206.

Enharmonic Diminished 7th Chords (cont.)

Move one note down a half-step to create a V7.
Notice the Beethoven example again. By moving the C down a half-step to B, he created the V7 in the new key. Had he wanted to go to a different key, he would have moved a different note down a half-step. See the example at the top of the next page.

Use a Gr+6 instead of a V7
Because a Gr+6 is enharmonic to a V7, it can be used to go to other keys. For example, in the example on p206, had Beethoven respelled the B7 chord as a Gr+6, it would create a modulation to D-sharp minor.

Enharmonic Secondary Diminished 7th Chords
Look at the Schubert example on p220. It begins in Ab major. In measure 40, there is a diminished 7th chord. It is not, however, vii°7. Instead, it is a secondary vii°7 that tonicizes V. In this example, Schubert uses a secondary diminished 7th as an enharmonic pivot. The chord also functions as the vii°7 in the new key, c minor.

Practice: WB p83: mm171–174; begins in D