Consonance and dissonance

Consonance and dissonance describe perceived stability or tension in combinations of musical tones. Their effects depend on acoustic properties, auditory perception, and musical context.

Beating: A fluctuation in sound intensity produced when tones with nearby frequencies interfere. Nearby partials create roughness through rapid beats, a major acoustic cue to dissonance.
Musical interval: The perceived distance in pitch between two musical tones. Consonance and dissonance are commonly discussed as qualities of intervals.
Pythagorean tuning: A tuning system that derives pitches through chains of perfect fifths based on simple frequency ratios. Its ratio-based account made numerical simplicity central to early explanations of consonance.
Cultural relativism in music: The view that musical meanings and judgments vary across cultural systems and practices. It challenges the idea that consonance judgments follow universally from acoustics alone.
Musical tuning: The process of setting the pitches of musical tones in relation to one another. Tuning choices determine which intervals have exact ratios and which distribute error.
Harmonic series: The sequence of whole-number multiples of a fundamental frequency present in many musical tones. Shared or aligned partials help explain why some tone combinations sound fused.
Frequency ratio: The numerical relationship between the frequencies of two periodic sounds. Simple ratios are often associated with consonant intervals, though not in every musical context.
Just intonation: A tuning approach that uses intervals formed from simple whole-number frequency ratios. It extends the idea that simple ratios produce especially consonant intervals.
Roughness theory of dissonance: An account that explains dissonance chiefly through interference among nearby frequency components. It explains sensory roughness but cannot by itself account for tonal tension.
Musical temperament: A tuning scheme that adjusts intervals to balance their consonance across musical keys. Temperaments manage the trade-offs between pure intervals and flexible modulation.

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