Minor third

The third of the minor sound

The minor third sounds warm, soft and slightly melancholy: exactly the muted sweetness that distinguishes minor from major. It is the basis of every minor triad, for example A minor: A–C–E, where A→C is a minor third. When a composition changes from major to minor, it happens through the alteration of this one interval, the third tone above the root. C major (C–E–G) becomes C minor (C–E♭–G) by turning E into E♭. This shift by just one semitone changes the whole effect.

The minor third is the inversion of the major sixth (5:3): add the two and you get exactly one octave. Together with the major third it makes a perfect fifth. Two minor thirds on top of each other form the diminished triad.

On the guitar

Three frets apart: if you fret the high E string (329.63 Hz) at the 3rd fret, G sounds at 392 Hz. Three frets are a common fingering distance in minor chords and blues licks. In pentatonic playing the minor third is one of the most characteristic intervals.

Just and equal-tempered

In just intonation the minor third lies 16 cents above the piano value. A minor chord that a wind section intones purely therefore sounds higher in the middle voice than on the keyboard instrument. If you hear both at the same time, you hear exactly the compromise a keyboard instrument has to make.

Common mistakes

• Mixing up minor and major third: Three against four semitones.
• Equating minor with “sad”: A great deal of dance music is in minor, and not every minor piece sounds sad.
• Taking two minor thirds for minor: That is a diminished triad.