In strict two-voice counterpoint, which of the following intervals is treated as a dissonance and must be carefully resolved?
AMajor third
BMinor sixth
CPerfect fourth
DPerfect fifth
The perfect fourth is treated as a dissonance in two-voice counterpoint because, without a lower voice to support it, it sounds unstable. Thirds and sixths are imperfect consonances (permitted freely), and the perfect fifth is a stable perfect consonance. This is the most common classification error students make.
Question 2 True / False
In counterpoint, a dissonant interval can appear anywhere in a passage as long as both voices move by step into and out of it.
TTrue
FFalse
Answer: False
Dissonances are permitted only in specific rhythmic positions (e.g., weak beats or as passing tones) and must be properly prepared and resolved according to the species being studied. Simply moving by step is necessary but not sufficient — placement and rhythmic context also matter.
Question 3 Short Answer
What is the fundamental difference between a harmonic interval and a melodic interval in counterpoint, and why does the distinction matter?
Think about your answer, then reveal below.
Model answer: A harmonic interval is the distance between two notes sounding simultaneously (vertical); a melodic interval is the distance a single voice moves between successive notes (horizontal). The distinction matters because consonance and dissonance rules govern harmonic intervals, while guidelines about leaps and stepwise motion govern melodic intervals.
Counterpoint requires thinking in both dimensions at once. A leap of a sixth in one voice (melodic) may be acceptable, but if it creates a dissonant seventh against the other voice (harmonic), that vertical result must be resolved. Confusing the two leads to incorrect analysis.