Degree V — Dom7 (Dominant)

Tension — wants to return to the tonic

Prove it — just do the practice exercise.
G7 Shell Voicing
G (R)B (3)F (♭7)
The V degree (dominant) creates maximum tension:

• In C major: G7
• Function: Tension → resolution to I
• Contains the tritone (B–F), which resolves to C–E

Roman numeral: V = dominant 7th chord

The V → I cadence is the foundation of Western music. In jazz, almost always as ii – V – I.