Fig. 1 · F# to G

interval

F♯ minor second

F♯lowerGupperm21 half steps

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

On the keyboard

GF#
Fig. 2

What is true of it

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

Turn it upside down — put the F♯ 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 F♯

F♯ → G♯major second · dissonanceF♯ → Aminor third · imperfect consonanceF♯ → A♯major third · imperfect consonanceF♯ → Bperfect fourth · perfect consonanceF♯ → B♯augmented fourth · dissonanceF♯ → Cdiminished fifth · dissonanceF♯ → C♯perfect fifth · perfect consonanceF♯ → Dminor sixth · imperfect consonanceF♯ → D♯major sixth · imperfect consonanceF♯ → Eminor seventh · dissonanceF♯ → E♯major seventh · dissonance

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