dissonanceintervals

Dissonance intervals are musical intervals traditionally regarded as unstable or tense-sounding, in contrast to consonant intervals which are perceived as stable and resolving more readily. The label and its exact boundary depend on musical era, tuning, and context. In Western tonal theory, certain intervals are commonly treated as dissonant, especially when they occur within a chord or harmony that seeks resolution.

Common dissonant intervals include the minor second (two adjacent semitones), the major second, the minor seventh (ten semitones), the major seventh (eleven semitones), and the tritone (an augmented fourth or diminished fifth). The tritone is often cited as the archetypal dissonance due to its highly unstable sound. Some traditions also treat augmented seconds as dissonant. Conversely, the perfect fourth is sometimes considered dissonant in certain contrapuntal contexts or voicings but is often treated as consonant in others, depending on its harmonic function.

Historically, the conception of dissonance has evolved with tuning systems and compositional practice. In medieval and Renaissance theory, dissonances were restricted and required careful preparation and resolution. In common-practice harmony, dissonances are typically allowed as passing tones, neighbor tones, suspensions, and other non-chord tones, but they must generally resolve to consonant tones by step. In more modern styles, such as jazz and contemporary classical music, dissonant intervals can be used more freely for color and tension, with resolution guided by stylistic conventions rather than strict voice-leading rules.

In analysis, dissonance intervals are evaluated by their roughness, harmonic function, and resolution tendency within a given melodic or harmonic context.