Pitch & Intervals

Minor Second

Written as m2

Definition

A minor second (m2) is an interval of one half step between neighboring letter names, such as E–F, B–C or C–D♭. It is the smallest interval in major and minor scales.

A minor second is the interval from one note to the next letter name, one half step away: E up to F, B up to C, F♯ up to G, C up to D♭. Abbreviated m2, it is the smallest interval in major and minor scales, and in equal temperament it measures 100 cents.

Three examples, each one bar of half notes: the lower note, the upper note, then both together: E4 and F4, B4 and C5 in treble clef, F sharp 3 and G3 in bass clef. — Three minor seconds, each played one note after the other and then together: E–F and B–C in the treble clef, F♯–G in the bass clef. Played together, the two noteheads sit side by side because they are only one step apart.

Counting it

Two checks name it. The letters are neighbors, so it is a 2nd. And there is exactly one half step between the notes: no key lies between them on the piano. If you count two half steps instead, you have a major second.

E to F: the very next key, 1 half step, with no black key between. A to B♭: from a white key to the black key just above it, also 1 half step.

How it sounds

Played one after the other, a minor second is the smallest, most "leaning" step a melody can take. The leading tone of a major key sits a minor second below the tonic (B–C in C major) and pulls up into it. Played together, the two notes grind against each other: the minor second is one of the strongest dissonances. Spread the notes an octave further apart and you get a minor ninth, still tense. Inverting the minor second instead gives a major seventh.

Film composers often use a slowly repeated minor second for menace; the theme from Jaws is the classic example. For a falling minor second, many students think of the first two notes of Beethoven's Für Elise.

Minor second or augmented unison?

C–D♭ and C–C♯ sound exactly the same on a piano. C–D♭ uses two letter names, so it is a minor second (a diatonic half step). C–C♯ uses one letter, so it is an augmented unison (a chromatic half step). Spell it the way the music moves: a line that goes C–D♭–C uses D♭, a line that climbs C–C♯–D uses C♯.

Inversion

Turn a minor second upside down and you get a major seventh: E–F becomes F–E. Their half steps add up to 12 (1 + 11), as every pair of inverted intervals does (see interval inversion).

Practice with Major & minor 2nds and 3rds and Name the intervals: major or minor.

Common questions

How many half steps is a minor second?

One. A minor second is the same distance as a half step: from any piano key to the very next key, as in E–F or C–D♭.

Is a minor second consonant or dissonant?

Dissonant. Played together, the two notes clash strongly, so a harmonic minor second usually appears briefly or resolves, for example as a passing or neighbor note.