So a half-diminished chord is written as Cø7, Fø7, Dø7, Gø7, or you could use m. Sometimes you see the chord written without the 7 — such as Cø or Ebø. Even though there’s no number 7 in the chord, it’s still a seventh chord because the ø symbol means “half-diminished,” and that has to be a seventh chord.

A half diminished chord is a four-note chord that consists of a root, a minor third, a diminished fifth, and a minor seventh. This chord is often represented by the symbol 'ø' or 'm7♭5', and it plays a crucial role in harmony, especially in minor scales.

Diminished chords almost always use a circle as their symbol: C° C°7 Cdim Cdim7 Half-Diminished chord symbols # Half-diminished chords usually take two forms, either a circle with a slash (cutting it in "half") or spelled out as a minor-7-flat-5 chord.

For a half-diminished seventh chord, we take the ° symbol and put a line through it, so it looks like this: ø 7. We can also write it as m7 b5, which means the same thing.