Perfect 5th (P5)

The perfect 5th: 7 semitones, the most stable leap — the backbone of power chords.

The perfect 5th spans 7 semitones. In just intonation its frequency ratio is 3:2; in equal temperament it measures 700 cents. Inverted, it becomes the perfect 4th. You can hear it inside chords such as Major, Minor, Power (5), 7.