Minor 2nd

General info

Interval

Minor 2nd

Quality

Minor

Semitones

1

Degree distance

2 degrees

Degree

b2

Interval structure

Lower note

A (440.0 Hz)

Lower note role

Root

Upper note

Bb (466.2 Hz)

Upper note role

Minor second (b2)

Degree formula

I

bII

Semitone formula

1 semitone

Interval construction

Interval formula

m2

Brief explanation

A minor second spans one semitone and joins adjacent scale degrees, such as E–F or B–C. Sounded together, it is a sharp dissonance; melodically, it is the smallest step in 12-tone equal temperament.

Interval notes

Consonance / dissonance

Sonority

Sharp dissonance

Explanation

The minor 2nd is a pronounced dissonance. Two notes are so close together that their frequencies create strong acoustic beating. This makes the interval extremely unstable and in need of resolution.

How the interval sounds

Tendencies & resolutions

Direction of resolution depends on the function of each pitch. The leading tone rises by semitone to tonic, while scale degree 4 in dominant harmony normally falls by semitone to 3.

Harmonic context

A minor second occurs between adjacent voices in suspensions and clusters; in tonal music it forms the motions 7–1 and 4–3. In Phrygian, b2 distinguishes the scale from natural minor.

Interval inversion

Inverts to

Major 7thM7

Quality change

Minor

major

Inversion rule

When inverting a minor 2nd, the lower note moves up an octave. A half step (m2) becomes 11 semitones — a major 7th (M7).

Related intervals