Inverse | diminished sixth |
---|---|

Name | |

Other names | - |

Abbreviation | A3^{[1]} |

Size | |

Semitones | 5 |

Interval class | 5 |

Just interval | 125:96,^{[2]} 21:16, 64:49 |

Cents | |

Equal temperament | 500 |

24 equal temperament | 500 |

Just intonation | 457 |

In classical music from Western culture, an **augmented third** (Play (help·info)) is an interval of five semitones. It may be produced by widening a major third by a chromatic semitone.^{[1]}^{[3]} For instance, the interval from C to E is a major third, four semitones wide, and both the intervals from C♭ to E, and from C to E♯ are augmented thirds, spanning five semitones. Being augmented, it is considered a dissonant interval.^{[4]}

Its inversion is the diminished sixth, and its enharmonic equivalent is the perfect fourth.

The just augmented third, E♯, is 456.99 cents or 125:96. Play (help·info) The Pythagorean augmented third, E♯+++, is 521.51 cents or 177147:131072, eleven just perfect fifths. Play (help·info)

## Sources

- ^
^{a}^{b}Benward & Saker (2003).*Music: In Theory and Practice, Vol. I*, p.54. ISBN 978-0-07-294262-0. **^**Haluska, Jan (2003).*The Mathematical Theory of Tone Systems*, p.xxvi. ISBN 0-8247-4714-3. Classic augmented third.**^**Hoffmann, F.A. (1881).*Music: Its Theory & Practice*, p.89-90. Thurgate & Sons. Digitized Aug 16, 2007. Archaically:**superfluous third**.**^**Benward & Saker (2003), p.92.