Fig. 1 · Gb to Abb

interval

G♭ minor second

G♭lowerA♭♭upperm21 half steps

One half step, written as a second: the smallest distance between two notes with different letters.

On the keyboard

A𝄫Gb
Fig. 2

What is true of it

G♭ up a minor second is A♭♭: 1 half step, and 2 letters counting both ends.

Turn it upside down — put the G♭ on top — and it becomes a major seventh. The two numbers always add to nine, and the two sizes to twelve.

It is a dissonance.

Every interval on G♭

G♭ → A♭major second · dissonanceG♭ → B♭♭minor third · imperfect consonanceG♭ → B♭major third · imperfect consonanceG♭ → C♭perfect fourth · perfect consonanceG♭ → Caugmented fourth · dissonanceG♭ → D♭♭diminished fifth · dissonanceG♭ → D♭perfect fifth · perfect consonanceG♭ → E♭♭minor sixth · imperfect consonanceG♭ → E♭major sixth · imperfect consonanceG♭ → F♭minor seventh · dissonanceG♭ → Fmajor seventh · dissonance

C m2C♯ m2D♭ m2D m2D♯ m2E♭ m2E m2F m2all 204