Outer Voice Counterpoint: Guidelines for Soprano and Bass Relationships

This lecture is presented by Dr. Doyle from Long Island, New York.
The focus is on outer voice counterpoint, specifically the relationship between the soprano and the bass.
The goal is to establish guidelines for proper melodic and harmonic relationships between these two primary voices.

Tendency tones are named for their strong inherent urge to move toward specific resolutions.
To maintain proper melodic and harmonic flow, composers should not leap away from these tones in the outer voices.
Scale Degree $7$ (The Leading Tone):
- In a $V^7$ chord, a $vii^{\circ}6$ , or a $vii^{\circ}7$ , the leading tone ( $7$ ) must resolve upward by step to the tonic ( $1$ ) when placed in either the soprano or the bass.
- It must never be doubled because both voices would then resolve to the same note, creating forbidden parallel octaves.
Scale Degree $4$ (The Chordal Seventh):
- In a dominant seventh chord ( $V^7$ ) or seventh chords based on the leading tone ( $vii^{\circ}6$ and $vii^{\circ}7$ ), scale degree $4$ has a strong urge to resolve downward by step to scale degree $3$ .
- Like the leading tone, scale degree $4$ should not be doubled in these specific chordal contexts to avoid parallel motion upon resolution.
Specific Progressions Discussed:
  - In $V^7$ and its inversions (such as $V^4_2$ ), $4$ resolves to $3$ .
  - In $vii^{\circ}6$ and $vii^{\circ}7$ , $4$ resolves to $3$ while $7$ resolves to $1$ .
  - If scale degree $4$ appears in a $IV$ chord rather than a dominant/leading-tone chord, the resolution rule is more flexible.

Definition: An unequal fifth occurs when a perfect fifth ( $P5$ ) is followed by a diminished fifth ( $d5$ ), or vice versa.
Reasoning: They are called "unequal" because they resemble similar motion rather than true parallel motion. This is due to the difference in semitone count: a $P5$ consists of $7$ semitones, while a $d5$ consists of $6$ semitones.
The Rule of Acceptance:
- Moving from a perfect fifth to a diminished fifth ( $P5 \rightarrow d5$ ) is considered acceptable.
- Moving from a diminished fifth to a perfect fifth ( $d5 \rightarrow P5$ ) is generally unacceptable.
Additional Caveat: It is best practice to avoid involving the bass voice in unequal voice motion, though some theory texts allow rare exceptions.
Directionality: Diminished fifths often contain two tendency tones that need to resolve inward rather than outward.

Independence of Voices: The primary reason for avoiding parallel perfect intervals is to maintain the melodic and rhythmic independence of the soprano and bass. When two voices move in parallel by the same perfect interval, they lose their distinct identities and sound like a single voice.
Contrary Motion: Using contrary motion does not bypass the rule. Movement from one perfect fifth to another perfect fifth in the opposite direction (e.g., one voice leaping down an octave while the other moves up) still constitutes forbidden parallel perfect intervals.
Beat-to-Beat Perfect Intervals: Parallelism is not broken up by inserting a note on a weak beat between two strong beats. If perfect fifths or octaves occur on successive strong beats, they are still considered parallel fifths/octaves.

Terminology: Also referred to as "Direct" or "Covered" fifths and octaves. The AP curriculum generally uses the term "Hidden."
Problem: These occur when the bass and soprano approach a perfect fifth or octave in similar motion, and the soprano voice reaches the interval by leaping (rather than by step).
Undesirability: The leap in the soprano makes the interval stand out too prominently, which is considered unrefined in traditional counterpoint.
Correct Approach: To reach a perfect fifth or octave safely, the soprano should move by step ( $2nd$ ).
Corrective Strategies:
- Use an inversion for the second chord to change the perfect interval into a consonant interval (like a $3rd$ or $6th$ ).
- Choose a different chord entirely to improve the voice leading.

Identify Intervals: Systematically identify every interval between the soprano and bass within each chord transition.
Determine Voice Involvement: Pinpoint which voices are producing perfect fifths or octaves.
Check Subsequent Intervals: If you find a perfect interval, look at where those same two voices move next. If they move to another perfect interval of the same type, you have parallel motion.
Check the Approach: For perfect intervals, look backward one chord. If the soprano reached that perfect interval via a leap, it is a hidden (direct) interval.

When adding a baseline to a given soprano, the harmonic movement must be plausible and logical. Dr. Doyle emphasizes using a reliable set of chord movements:
The "Safe" Chord Box (Recommended for practice):
- $I, ii, IV, V, vi, V^7$ (and its inversions).
Rules for Chord Progression:
  - Descending Fifths (Strongest): Chords can move down by a fifth. Examples: $I \rightarrow IV$ , $ii \rightarrow V$ , $vi \rightarrow ii$ .
  - Ascending Fifth Exceptions: Chords can move up by a fifth in specific cases: $I \rightarrow V$ and $IV \rightarrow I$ .
  - Ascending Seconds: Chords can move up by a second. Examples: $I \rightarrow ii$ , $IV \rightarrow V$ , $V \rightarrow vi$ .
  - Descending Second Exception: The movement $vi \rightarrow V$ is an acceptable exception to the ascending second rule.
  - Descending Thirds: Chords can move down by a third. Examples: $I \rightarrow vi$ , $vi \rightarrow IV$ , $IV \rightarrow ii$ .
  - Note on Ascending Thirds: In the current stage of study, avoid ascending thirds (e.g., $V \rightarrow vii$ or $ii \rightarrow IV$ ).

Direct Fifth: A perfect fifth approached by a leap in the soprano.
Beat-to-Beat Perfect Fifths: Perfect fifths on consecutive beats where the passing note fails to break the parallel motion.
Voice Overlap: A situation where a voice moves to a note higher or lower than the previous note held by an adjacent voice (e.g., the soprano moving below where the alto was, or the tenor moving below the bass's previous note).
Parallel Fifths in Contrary Motion: Reaching a perfect fifth from another perfect fifth while moving in opposite directions.
Unequal Fifths Error: Reaching a perfect fifth from a diminished fifth ( $d5 \rightarrow P5$ ).
Irregular Doubling: Doubling the leading tone ( $7$ ).

Avoid hidden/direct fifths and octaves (approach by step in the soprano).
Avoid parallel fifths and octaves in both similar and contrary motion.
$P5 \rightarrow d5$ is allowed; $d5 \rightarrow P5$ is not.
Tendency tones in outer voices must resolve properly: $4 \rightarrow 3$ and $7 \rightarrow 1$ .
All dissonances and chromatic notes in outer voices must resolve by step.
When harmonizing, use Roman numerals that imply strong, logical harmonic movement.