Fifteenth
In music, a fifteenth or double octave, abbreviated 15ma, is the interval between one musical note and another with one-quarter the wavelength or quadruple the frequency. It has also been referred to as the bisdiapason. The fourth harmonic, it is two octaves.
Extends: Octaves, [Perfect intervals](https://wikipedia.org.ai/Perfect intervals), [Compound intervals](https://wikipedia.org.ai/Compound intervals)
Properties
| Property | Expected Type | Description |
|---|---|---|
| [Main Interval Name](https://wikipedia.org.ai/Main Interval Name) | Text | Perfect fifteenth |
| Abbreviation | Text | P15 |
| Semitones | Text | 24 |
| [Interval Class](https://wikipedia.org.ai/Interval Class) | Text | 0 |
| [Just Interval](https://wikipedia.org.ai/Just Interval) | Text | 4:1 |
| [Cents Equal Temperament](https://wikipedia.org.ai/Cents Equal Temperament) | Text | 2400 |
| [Cents 24t Equal Temperament](https://wikipedia.org.ai/Cents 24t Equal Temperament) | Text | 2400 |
| [Cents Just Intonation](https://wikipedia.org.ai/Cents Just Intonation) | Text | 2400 |