{{Infobox Interval| main_interval_name = Augmented third| inverse = diminished sixth| complement = diminished sixth| other_names = -| abbreviation = A3<ref name="B&S"/>| semitones = 5| interval_class = 5| just_interval = 125:96,<ref name="Haluska">Haluska, Jan (2003). ''The Mathematical Theory of Tone Systems'', p.xxvi. {{ISBN|0-8247-4714-3}}. Classic augmented third.</ref> 21:16, 64:49| cents_equal_temperament = 500| cents_24T_equal_temperament = 500| cents_just_intonation = 457 }}In classical music from Western culture, an '''augmented third''' ({{audio|Fourth_ET.ogg|Play}}) is an interval of five semitones. It may be produced by widening a major third by a chromatic semitone.<ref name="B&S">Benward & Saker (2003). ''Music: In Theory and Practice, Vol. I'', p.54. {{ISBN|978-0-07-294262-0}}.</ref><ref>Hoffmann, F.A. (1881). ''Music: Its Theory & Practice'', p.89-90. Thurgate & Sons. Digitized Aug 16, 2007. Archaically: '''superfluous third'''.</ref> For instance, the interval from C to E is a major third, four semitones wide, and both the intervals from C{{Music|b}} to E, and from C to E{{Music|sharp}} are augmented thirds, spanning five semitones.

:<score sound> { \override Score.TimeSignature #'stencil = ##f \relative c' { \time 4/4 \set Score.tempoHideNote = ##t \tempo 1 = 20 <ces e>1 <c? eis> } } </score>

Being augmented, it is considered a dissonant interval.<ref>Benward & Saker (2003), p.92.</ref>

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

The just augmented third, E{{music|#}}, is 456.99 cents or 125:96. {{audio|Just augmented third on C.mid|Play}} The Pythagorean augmented third, E{{music|#}}{{music|plus}}{{music|plus}}{{music|plus}}, is 521.51 cents or 177147:131072, eleven just perfect fifths. {{audio|Pythagorean augmented third on C.mid|Play}}

==References== <references/>

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{{DEFAULTSORT:Augmented third}} Category:Augmented intervals Category:Thirds (music) {{music-theory-stub}}