Interval
Perfect octave
Twelve semitones. The interval at which pitches feel like 'the same note' — the doubling ratio 2:1. Any scale is defined within one octave.
Semitones
12
Frequency ratio
2:1
Listening examples
- 'Somewhere Over the Rainbow' opening leap
- C4 → C5 on piano
Hear this interval from any tonic on any instrument: browse the intervals reference →
Adjacent intervals