In most music a dissonance will resolve; it will be followed by a consonant chord that it naturally leads to, for example a G seventh chord resolves to a C major chord, and a D suspended fourth resolves to a D major chord.

What intervals are dissonant?

Dissonance is a combination of notes that sound unpleasant or harsh. Dissonant interval examples are major and minor seconds, tritone, and major and minor sevenths. The consonant intervals are considered the perfect unison, octave, fifth, fourth and major and minor third and sixth, and their compound forms.

Why do some intervals sound dissonant?

If the two notes are dissonant because their frequencies overlap instead of blending together, they create an uneven (offbeat) vibration inside our ear and the brain feels unsettled.