Questions: Contrapuntal Melody Combination

Question 1

A student writes a two-voice passage where both voices move upward together, then downward together, maintaining consonant intervals throughout. What is the primary contrapuntal problem?

• A. The voices create too many dissonances by moving in the same direction
• B. The voices lose melodic independence, sounding like one doubled melody rather than two distinct lines
• C. The bass line moves too rapidly for the upper voice to follow coherently
• D. Parallel motion always produces forbidden parallel fifths or octaves

Answer: (B)

Consistent parallel motion — both voices moving in the same direction — undermines melodic independence even when the harmonic intervals are consonant. The two voices begin to function as a single thickened melody rather than two independent characters. This is why contrary motion is the primary tool of counterpoint: it preserves the sense of two distinct voices in conversation. Note that parallel motion does not automatically create parallel fifths — parallel thirds are acceptable — but consistent parallel motion still compromises independence.

Question 2

A student carefully avoids parallel fifths and octaves in a two-voice piece, but both voices always move in the same direction. Their teacher still criticizes the counterpoint. Why?

• A. Because parallel motion at any interval implies hidden fifths at phrase endings
• B. Because even without parallel fifths or octaves, parallel motion erodes the independence that makes counterpoint two distinct voices
• C. Because parallel thirds and sixths are also prohibited in strict counterpoint
• D. Because the teacher is applying rules from a different historical style period

Answer: (B)

Avoiding parallel fifths and octaves is necessary but not sufficient for good counterpoint. The deeper goal is melodic independence — making each voice sound like a distinct entity that could be heard and sung on its own. Constant parallel motion undermines this even when specific forbidden intervals are absent. The test of good counterpoint is not just interval-correctness but whether each voice has its own melodic character: its own contour, rhythmic identity, and sense of direction.

Question 3

Parallel fifths and octaves are prohibited in counterpoint primarily because they make the music sound dissonant.

• T. True
• F. False

Answer: False

Parallel fifths and octaves are actually quite consonant intervals — that's the problem. They are prohibited because they cause the voices to merge, temporarily sounding like a single voice rather than two independent lines. When two voices move in parallel octaves, one doubles the other; parallel fifths produce a hollow, fused texture. The prohibition is about preserving voice independence, not avoiding dissonance. Parallel thirds and sixths are consonant and generally acceptable precisely because they preserve registral separateness.

Question 4

Contrary motion is the most effective technique for maintaining voice independence in two-part counterpoint.

• T. True
• F. False

Answer: True

Contrary motion — one voice ascending while the other descends — is the primary tool for keeping voices independent. When voices move in opposite directions, they naturally maintain distinct melodic identities and avoid the merging effect of parallel motion. Contrary motion also structurally helps avoid parallel fifths and octaves. In Bach's two-part inventions, contrary motion appears throughout as the signature of well-crafted independent voices. It is the foundational technique for reasserting voice independence whenever the texture risks collapsing.

Question 5

Why is contrary motion the most powerful tool for maintaining melodic independence in two-part counterpoint? What happens to the listener's experience when voices consistently move in parallel instead?

Model answer: Contrary motion keeps voices moving in opposite directions, preventing them from tracking each other and collapsing into a single entity. When one voice ascends as the other descends, each has its own direction and melodic character — a listener can follow either voice independently. With consistent parallel motion, the voices lose this separateness and begin to sound like one melody doubled at an interval, undermining the whole premise of counterpoint as the combination of independent melodic lines.

The goal of counterpoint is two simultaneous musical conversations, not one conversation in two-part harmony. Contrary motion is the sonic signal of true independence: the voices are making different decisions at each moment. Parallel motion signals coordination — the voices are doing the same thing at different pitch levels. In practice, good counterpoint alternates motion types, but contrary motion is the default tool when independence needs to be reasserted, which is why it dominates the texture of Bach's two-part inventions.