AP Music Theory: Secondary Leading Tone Chords & Modulation - Your Ultimate Review 🚀

Hey there, future music maestro! Let's get you feeling super confident about secondary leading tone chords and modulation. This guide is designed to be your go-to resource for a last-minute review, so let's dive in!

Secondary Leading Tone Chords

Remember how much we love the dominant function of V and vii°? Well, get ready to take that love to the next level with secondary leading tone chords! These chords help us create a stronger sense of tonicization. Think of them as the spicy version of your regular leading tone chords.

What are they?

• Secondary leading tone chords (vii°/X) function just like regular vii° chords but in a temporary key.
• They usually appear as seventh chords: vii°⁷ and viiø⁷.
• In major keys, both vii°⁷ and viiø⁷ are fair game. In minor keys, stick to vii°⁷.
• Fully diminished seventh chords (vii°⁷) are more common.

Example in B Major

Let's say we're in B major and want to tonicize the IV chord (E major).

• The leading tone in E major is D#.
• vii°/IV: D#-F#-A♮
• vii°⁷/IV: D#-F#-A♮-C♮
• viiø⁷/IV: D#-F#-A♮-C#

Identifying Secondary Leading Tone Chords

1. Spot the Accidentals: If you see accidentals, it's a sign you might be dealing with a secondary chord.
2. Is it Diminished/Half-Diminished?: If yes, and there are accidentals, you've likely found a secondary leading tone chord. Remember, V chords are usually major.

Brahms Example

Let's analyze a snippet from Brahms' Intermezzo, op 119 no. 3 in C major:

• Measure 1: V⁷ (G-B-D-F) and I⁶₄ (passing chord).
• Measure 2:
  • Beat 1: iiø⁶₅ (F-Ab-C-D)
  • Beat 2: vii°⁷/V (F#-A-C-E), because F# is the leading tone of G (V of C).
• Measure 3: V⁷ (G-B-D-F) and I⁶₄ (passing chord).

Part Writing Secondary Leading Tone Chords

Follow all your regular voice-leading rules, but with a twist! Remember, we're in a temporary key, so your leading tone, chordal seventh, and tonic will be different.

Key Considerations

• No half-diminished 7th in minor keys: Use vii°⁷ instead.
• Avoid vii°/III and viiø⁷/III in minor: They sound like ii° and iiø⁷.
• No viiø⁷/V in minor: This would require raising and not raising the leading tone in the same chord.
• Avoid root position vii°⁷: Just like in regular voice leading, they are generally not considered good practice in 18th century voice leading.
• Always raise the leading tone in secondary leading tone chords to emphasize the pull to the temporary tonic.

Tonicizing Deceptive Motion

Sometimes, a deceptive cadence gets a little extra with a tonicization. For example, V-vii°/vi-vi. Why?

• V to vii°/vi has many common tones, making the motion smooth.
• vii°/vi to vi sounds more conclusive than V to vi because of the vii-i motion in the secondary key.

Example

Let's look at an example from Josephine Lang's “Mag da draussen senhee”:

• V⁷ in the primary key (Ab-C-Eb-Gb).
• vii°⁷/vi (A♮-C-Eb-Gb) in the secondary key of Bb minor. Note that even though this chord is in root position, it is usually not considered good practice to write a root position viio7 chord in 18th century voice leading.
• Leading tones resolve upwards, and the chordal seventh resolves downwards.

Practice Time! 🦜

Try this: Write a vii°/V-V chord progression in any key. Then, add cadential 6/4 chords. Try it with seventh chords too! (vii°/V-V⁶/₄-⁵/₃ and vii°/V-V⁸/⁶/₄-⁷/⁵/₃)

Introduction to Modulation

Modulation is when you actually change keys for a longer period, unlike tonicization, where you just borrow a few chords. Usually, we modulate to closely related keys.

Modulation to Distantly Related Keys

• Use harmonic sequences (like ascending or descending fifths) to move along the circle of fifths.
• These sequences can be viewed as a series of tonicizations (e.g., I-V-vii-iii-vi-ii can be I-V-vii-V/vii-vi-V/vi).
• Ascending seconds sequences can use secondary leading tone chords.

Modulation is a big topic on the AP exam! Make sure you understand how to modulate to closely and distantly related keys.

Modern Modulation

Some composers, like Rachmaninov, modulate to distantly related keys without harmonic sequences. This creates a sudden, dissonant sound. It's an artistic choice, but not recommended when you're first learning modulation!

Final Exam Focus

Okay, here's the lowdown on what to focus on for the exam:

• Secondary Leading Tone Chords: Identifying them, part-writing them, and understanding their function in tonicization.
• Tonicization: How secondary dominants and leading tone chords create temporary tonics.
• Modulation: Understanding how to modulate to closely and distantly related keys. Harmonic sequences are your friends!
• Voice Leading: Keep those voice-leading rules in mind, especially when dealing with accidentals.

Last-Minute Tips

• Time Management: Don't get bogged down on one question. Move on and come back if you have time.
• Common Pitfalls: Watch out for incorrect accidentals and root position vii°⁷ chords.
• Strategies: For FRQs, plan your answer before you start writing. For MCQs, eliminate wrong answers first.

Practice Questions

Practice Question

Multiple Choice Questions

1. In the key of A major, which of the following is the correct spelling of vii°⁷/V? (A) G#-B-D-F (B) G#-B-D-F# (C) G#-B#-D-F (D) G#-B-D#-F

2. Which of the following is the most common function of a secondary leading tone chord? (A) To prolong the tonic chord (B) To create a deceptive cadence (C) To tonicize a chord other than the tonic (D) To modulate to a distantly related key

Free Response Question

Analyze the following four-part harmony excerpt. Include Roman numeral analysis, and identify any secondary chords and modulations. Provide a harmonic analysis of the excerpt, including the key, cadence types, and any modulations or tonicizations present. Be sure to label all chords with Roman numerals, including inversions and secondary functions.

Scoring Breakdown

• Correct Key Identification: (1 point)
• Correct Roman Numeral Analysis: (1 point per chord, including inversions and secondary functions. Max 6 points)
• Identification of Cadence Types: (1 point per cadence. Max 2 points)
• Identification of Modulation: (2 points)
• Clarity and Accuracy of Analysis: (1 point)

Total: 12 points

Alright, you've got this! Go ace that exam! 🌟

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