ChordWizard® Music Theory 3.0 is the downloadable version of the How Music Works tutorials. It is installed on your computer for easy reference, and includes all the sounds, text searching, bookmarking, and many printing options.

(3.1) Interval Sizes

There are many different interval sizes, each with a different sound. Interval names are based on the notes in the Major scale.

Shown below are the interval sizes up to an octave (measured in semitones) with a brief description of their sound.

Unison intervals are two identical notes played together. They are always strongly consonant, and difficult to tell apart.

Minor second intervals are strongly dissonant, with a warbling sound in the background, as if the two notes are fighting with each other.

Second intervals are less dissonant, but the notes still do not sit completely at ease with each other.

Minor third intervals are strongly consonant, with a melancholy flavour to the sound. They form the basis of minor chords and scales.

Major third intervals are strongly consonant, making a stable and pleasing sound. They form the basis of major chords and scales.

Perfect fourth intervals are mildly dissonant, with a stretched feeling as if they would rather return to a major third.

Tritone intervals are dissonant, and are often found in chords of four notes or more, where they add a particular harmonic spice.

Perfect fifth intervals are strongly consonant, and are found in both minor and major chords. They add solidness, but not much character to the harmony.

Minor sixth intervals are mildly dissonant.

Major sixth intervals are consonant.

Minor seventh intervals are mildly dissonant.

Major seventh intervals are dissonant.

Octave intervals are strongly consonant, like unison, because notes an octave apart sound similar to each other, just higher or lower.