Which interval is identified as dissonant in the material, illustrating a broader dissonant class?

• A. Major Third
• B. Minor Third
• C. Major Seventh
• D. Perfect Fifth

Answer: (C)

Dissonant intervals create tension that seeks resolution to a stable pitch. The major seventh fits this idea best because, above a root, it sounds unstable and pulls strongly to resolve up to the octave. In tonal harmony, the upper note of a major seventh acts like a leading tone, leading the harmony toward the tonic by moving a half step. The other options—major third, minor third, and perfect fifth—sound smooth and stable, forming the common, consonant sounds of triads and octaves. So the interval identified as dissonant is the major seventh.