A half-diminished seventh chord is constructed with a root, a minor third, a diminished fifth, and a diminished seventh.

The half-diminished seventh chord built on C consists of the notes C, E♭, G♭, and B♭.

F major seventh is not a half-diminished seventh chord because it contains a major seventh instead of a diminished seventh.

Half-diminished seventh chords are often used as leading tone chords, resolving to dominant chords.

Half-diminished seventh chords most commonly resolve to dominant chords, creating a strong sense of harmonic movement.

The progression I - vi - ii - V - I contains a half-diminished seventh chord, specifically the ii chord.

The main difference between a half-diminished seventh chord and a diminished seventh chord is the quality of the third and fifth intervals.

Half-diminished seventh chords are commonly used in jazz as substitutes for dominant seventh chords, as passing chords, and as turnaround chords.

The harmonic minor scale contains a half-diminished seventh chord built on the seventh degree of the scale.

A half-diminished seventh chord is enharmonically equivalent to a diminished seventh chord.

The B half-diminished seventh chord is built on the seventh degree of the G major scale.

The half-diminished seventh chord built on F consists of the notes F, A, C, and E♭.

C major seventh is not a half-diminished seventh chord because it contains a major seventh instead of a diminished seventh.

Half-diminished seventh chords are often used as subdominant chords in modal contexts, providing a sense of movement and resolution.

The progression I - vi - ii - V - I contains a half-diminished seventh chord, specifically the ii chord.