Degree vii° — m7♭5 (Dominant Sub)
Half-diminished — rare but important
Prove it — just do the practice exercise.
Bm7b5 Shell Voicing
B (R)D (♭3)A (♭7)
The vii degree is half-diminished:
• In C major: Bm7♭5 (Bø7)
• Function: Dominant substitute
• Contains the same tritone as V7 (B–F)
• In minor: ii chord (e.g. Bø7 → E7 → Am)
Roman numeral: vii° (half-diminished)
The vii° is rarely used alone, but is central to minor ii-V-I progressions.
• In C major: Bm7♭5 (Bø7)
• Function: Dominant substitute
• Contains the same tritone as V7 (B–F)
• In minor: ii chord (e.g. Bø7 → E7 → Am)
Roman numeral: vii° (half-diminished)
The vii° is rarely used alone, but is central to minor ii-V-I progressions.