AP Music Theory: Voice Leading - Your Ultimate Guide 🎶

Hey there, future maestro! Let's get you feeling confident about voice leading for your AP Music Theory exam. This guide is designed to be your go-to resource, especially the night before the test. We'll break down complex topics into easy-to-digest pieces, with plenty of visuals and memory aids to help you ace it!

Introduction to Voice Leading

When writing music, we need to consider:

• Correct chord spelling: Make sure you have the right notes in each chord.
• Spacing: How close or far apart the notes are.
• Doubling: Which notes are repeated in the chord.

Good voice leading aims for:

• Linear smoothness: No big, unexpected jumps between notes.
• Independence of voices: Each voice should have its own melodic line, not just copying another.

Soprano-Bass Counterpoint

Focusing on the relationship between the soprano (highest) and bass (lowest) lines is key. These outer voices provide the harmonic framework. Think of them as the musical pillars of your composition.

Here's a typical four-part harmony example (SATB): Soprano, Alto, Tenor, Bass.

• Soprano: Top notes with stems up in the treble clef.
• Alto: Lower notes with stems down in the treble clef.
• Tenor: Notes with stems up in the bass clef.
• Bass: Notes with stems down in the bass clef.

Cadences

Types of Motion

How voices move relative to each other:

1. Parallel Motion: Voices move in the same direction by the same interval.

   

2. Similar Motion: Voices move in the same direction, but not by the same interval.

   

3. Oblique Motion: One voice stays still while the other moves.

   

4. Contrary Motion: Voices move in opposite directions.

   

Voice Leading Rules for Outer Voices

• Stepwise Motion: Voices should move mostly by step, avoiding excessive leaps.
• Common Tones: Keep common tones in the same voice when possible.
• SATB Order: Maintain Soprano-Alto-Tenor-Bass order to avoid voice crossing.
• Avoid Parallel Fifths and Octaves: If a perfect fifth or octave is not immediately repeated, don't move to another one in parallel motion. This also applies to contrary motion.
• Melodic Intervals: Use major and minor 2nds/3rds, perfect 4ths/5ths. Avoid augmented/diminished intervals and leaps larger than a perfect 5th.
• Leading Tone Resolution: Leading tones in outer voices must resolve up by step to the tonic.
• Leading Tone Doubling: Avoid doubling the leading tone, and make sure it resolves correctly.
• Dissonances: Avoid dissonances, especially augmented and diminished intervals (tritones) between outer voices. Fourths, major/minor 7ths and 2nds are generally okay.
• Cross-Relations: Avoid cross-relations, where a note is followed by its chromaticized version in another voice.

Bass Line Rules

• Harmonic Sense: Bass notes must make harmonic sense with the soprano line.
• Acceptable Chords: Use tonic, supertonic, subdominant, and dominant triads.
• Repeated Harmonies: Repeated chords are okay on strong beats (or weak beats at the start of a phrase).
• Melodic Interest: Balance upward/downward motion, steps and leaps.
• Leaps: Bass lines use more leaps than upper voices (3rds, 4ths, 5ths, 6ths, 8ves, and resolved descending diminished 5ths).
• Octave Leaps: Follow octave leaps with a change in direction.
• Triad Leaps: Successive leaps can outline a triad.
• Repeated Bass Notes: Okay on strong beats (or weak beats at the start of a phrase or as a suspension).
• Rhythm: Quarter notes are the most common, but use half and eighth notes too.

Notating the Outer Voices

• Listen Carefully: Identify the soprano and bass lines first.
• Stepwise Motion: Top voice usually moves by step.
• Big Leaps: Big leaps usually indicate the bass line.
• Chord Identification: Once you have the outer voices, you can figure out the chords and inversions.
• Educated Guesses: If unsure, make educated guesses based on chord progression rules.

Chord Positions

• Closed Position: Upper voices (soprano, alto, tenor) are as close as possible.
• Open Position: Any other spacing.

Final Exam Focus

• Voice Leading Rules: Master the rules for parallel motion, contrary motion, etc. Pay special attention to parallel 5ths and 8ves.
• SATB Writing: Understand how to write in four parts (soprano, alto, tenor, bass) and follow the rules for each voice.
• Bass Line Creation: Practice creating bass lines from given soprano lines.
• Chord Positions: Know the difference between open and closed positions.

Last-Minute Tips

• Time Management: Don't spend too long on one question. Move on and come back if needed.
• Common Pitfalls: Watch out for parallel 5ths and 8ves, unresolved leading tones, and cross-relations.
• Strategies: Start with the outer voices when analyzing. Listen for stepwise motion in the soprano line and leaps in the bass line.

Practice Questions

Practice Question

Multiple Choice Questions

1. Which type of motion is characterized by two voices moving in the same direction, but by different intervals? (A) Parallel motion (B) Similar motion (C) Oblique motion (D) Contrary motion

2. In four-part writing, which interval should be avoided between outer voices? (A) Perfect fourth (B) Minor seventh (C) Major second (D) Tritone

3. When creating a bass line, which of the following is generally NOT acceptable? (A) Leaps of a perfect fifth (B) Repeated notes on a strong beat (C) Successive leaps outlining a triad (D) Leaps of a major seventh

Free Response Question

Given the following soprano line in C Major, create a bass line that adheres to the rules of voice leading. Include figured bass notation below the bass line.

(Image of a simple soprano line in C Major, 4 measures, with a few stepwise motions and simple rhythms)

Scoring Breakdown:

• Bass Line (8 points):
  • 1 point for each measure with correct bass note and rhythm.
  • 1 point for proper melodic motion (steps and leaps).
  • 1 point for avoiding parallel 5ths and 8ves between the outer voices.
• Figured Bass (4 points):
  • 1 point for each measure with correct figured bass notation.

Short Answer Question

Explain the difference between open and closed position in four-part writing. Provide an example of each.