Extended tertian chords are chords built in thirds that go beyond seventh chords, constructed by placing additional thirds above the seventh. Adding thirds to a seventh chord does not change the chord’s function. Instead, the extended tertian chords create a different “color” or “sound” for the same function.

For instance, the extended tertian sonorities V9, V9, V11, V13, and V13 all have dominant function, just like the V7 chord.. All of these chords are possible in the major mode; however, only V9 and V13 occur in the minor mode and may also appear as borrowed chords in major keys.

The ii9 chord functions predominantly, like the ii and ii7. It is found only in major keys, often preceding the V13 chord.

Overview of how to spell extended tertian chords

When writing in four voices (SATB) with extended tertian chords, place the most extended note (e.g., the ninth, eleventh, or thirteenth) in the soprano voice. Since extended tertian chords involve more than four notes, some members must be omitted in a four-voice texture:

• Ninth chords: omit the fifth [rendering Root – 3rd – 7th – 9th]
• Eleventh chords: omit the third and the fifth [rendering Root – 7th – 9th – 11th]
• Thirteenth chords: omit the fifth, ninth and eleventh [rendering Root – 3rd – 7th – 13th]

Finally, extended tertian chords will typically appear in root position. Avoid using inversions with extended tertian chords.

Dominant ninths and thirteenths

Study the following examples, which show how to resolve and voice each type of extended tertian chord. For ninth and thirteenth chords, it is customary to use the root, third, seventh, and most extended note (the ninth or thirteenth above the root, respectively). Example 47-1 shows the V9. As with all ninth chords, we spell the V9 with root, third, seventh, and ninth when writing in four voices.

Example 47‑1. V9

Example 47-2 features an exciting V9 near the end of the second movement of Haydn’s Herbst (Autumn) from Die Jahrzeiten (The Seasons) in vocal score (orchestral reduction) format. The chord is highlighted in the example, and annotations showing lead sheet symbols and corresponding Roman numerals are provided. Video T91 explores this passage using the full orchestral score in the analysis.

The V9 features the same voice leading and chord members (root, third, seventh, ninth) as the V9, as shown in Example 47-3. The only difference between the V9 and V9 is is whether the ninth above the root is major or minor.

Example 47-4 shows the V9 used three times in the first phrase of “Close Every Door” from Joseph and the Amazing Technicolor Dreamcoat. This example is in F minor, and the V9 is spelled C – E – B – D in four voices. Video T92 walks you through Examples 47-3 and 47-4.

The V13, shown in Example 47-5, features the root, third, seventh, and thirteenth, and the soprano typically resolves down from scale degree (the chordal thirteenth) to tonic (the root of the tonic triad). Often composers will connect these notes by step, passing through scale degree .

Example 47-6 features a V13 chord in the key of G major near the end of the excerpt. Video T93 walks you through Examples 47-5 and 47-6, which explore the V13.

The V13 works just like the V13. The only difference in spelling these chords involves the thirteenth above the root: major (MA13) in the V13 and minor (mi13) in the V13.

Example 47-8 features many chromatic chords, including an augmented sixth chord and a Neapolitan chord, in addition to the V13 in the second-to-last measure. This passage is in the key of C minor, and in this key, the V13 is spelled G – B – F – E. Notice the E is featured in the melody and moves through D (scale degree ) before resolving to C (tonic). Video T94 explores the V13 and its use in Example 47-8.

Dominant eleventh and supertonic ninth

In contrast to ninth and thirteenth chords, eleventh chords omit the third and fifth in four-part textures, using the root, seventh, ninth, and eleventh. Another way of thinking about spelling the V11 is to use scale degree in the bass, with the notes from the subdominant triad above it (scale degrees , , and ). Example 47-9 shows the spelling and resolution of the V11 in F major. Video T95 walks you through this example and Example 47-10.

Spell the V11 and its resolution in A major, and listen for this progression near the end of the chorus section in Example 47‑10. Select the right arrow over the image below to view the answer.

Like the other ninth chords we have studied, the supertonic ninth chord (ii9) uses the root, third, seventh, and ninth in four-part textures. It often connects to a V13, as the soprano note (scale degree , or “mi”) is the same in both the ii9 and V13. Example 47-11 shows the spelling and resolution of the ii9 in the key of F major. Video T96 explores Example 47-11 and how the ii9 works in a repeating progression in Example 47-12.

Realize the ii9 – V13 – IMA7 progression in C major, which is featured in Example 47-12. Select the right arrow over the image below to view the answer.

Altered dominants

Altered dominants (some of which are referred to as “added note chords”) function similarly to dominant extended tertian chords because they share the dominant scale degree as root and substitute for any regular dominant chord. The most common altered dominants are Vadd6 (the dominant triad plus a sixth above the bass), V+ (an augmented triad built on scale degree ), and V+7 (an augmented triad built on with a chordal seventh). These chords appear in root position.