Semitone

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: "Semitone" – news · newspapers · books · scholar · JSTOR  (May 2021) (Learn how and when to remove this template message)

Semitone

A semitone, also called a half step or a half tone,<a href="#cite_note-3" style="counter-reset: mw-Ref 3;">[3]</a> is the smallest <a href="/en/Interval_(music)" title="Interval (music)" class="wl">musical interval</a> commonly used in Western tonal music,<a href="#cite_note-4" style="counter-reset: mw-Ref 4;">[4]</a> and it is considered the most <a href="/en/Consonance_and_dissonance#Dissonance" title="Consonance and dissonance" class="wl">dissonant</a><a href="#cite_note-5" style="counter-reset: mw-Ref 5;">[5]</a> when sounded harmonically.
It is defined as the interval between two adjacent notes in a <a href="/en/Chromatic_scale" title="Chromatic scale" class="wl">12-tone scale</a>. For example, C is adjacent to C♯; the interval between them is a semitone.

<style data-mw-deduplicate="TemplateStyles:r1033289096" typeof="mw:Extension/templatestyles mw:Transclusion">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}</style>
<style data-mw-deduplicate="TemplateStyles:r1097763485" typeof="mw:Extension/templatestyles mw:Transclusion">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}html.client-js body.skin-minerva .mw-parser-output .mbox-text-span{margin-left:23px!important}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}</style>
<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt15">Musical interval</div><style data-mw-deduplicate="TemplateStyles:r1066479718" typeof="mw:Extension/templatestyles">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}body.skin-minerva .mw-parser-output .infobox-header,body.skin-minerva .mw-parser-output .infobox-subheader,body.skin-minerva .mw-parser-output .infobox-above,body.skin-minerva .mw-parser-output .infobox-title,body.skin-minerva .mw-parser-output .infobox-image,body.skin-minerva .mw-parser-output .infobox-full-data,body.skin-minerva .mw-parser-output .infobox-below{text-align:center}</style><div class='mobile-collapse'><header class="mobile-collapse-header mobile-collapse-btn">Quick facts: Inverse, Name, Other names, Abbreviation, Siz... ▼</header> <table class="infobox mobile-collapse-element"><caption class="infobox-title">semitone</caption><tbody><tr><th scope="row" class="infobox-label"><a href="/en/Inversion_(interval)" title="Inversion (interval)" class="mw-redirect wl">Inverse</a></th><td class="infobox-data"><a href="/en/Major_seventh" title="Major seventh" class="wl">major seventh</a> (for minor second); <a href="/en/Diminished_octave" title="Diminished octave" class="wl">diminished octave</a> (for augmented unison); <a href="/en/Augmented_octave" title="Augmented octave" class="wl">augmented octave</a> (for diminished unison)</td></tr><tr><th colspan="2" class="infobox-header notheme" style="background-color:palegoldenrod;">Name</th></tr><tr><th scope="row" class="infobox-label">Other names</th><td class="infobox-data">minor second, diatonic semitone, augmented unison, diminished unison, chromatic semitone</td></tr><tr><th scope="row" class="infobox-label">Abbreviation</th><td class="infobox-data">m2; A1</td></tr><tr><th colspan="2" class="infobox-header notheme" style="background-color:palegoldenrod;">Size</th></tr><tr><th scope="row" class="infobox-label"><a href="/en/Semitone" title="Semitone" class="wl">Semitones</a></th><td class="infobox-data">1</td></tr><tr><th scope="row" class="infobox-label"><a href="/en/Interval_class" title="Interval class" class="wl">Interval class</a></th><td class="infobox-data">1</td></tr><tr><th scope="row" class="infobox-label"><a href="/en/Just_intonation" title="Just intonation" class="wl">Just interval</a></th><td class="infobox-data">16:15,<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a> 17:16,<a href="#cite_note-Haluska-2" style="counter-reset: mw-Ref 2;">[2]</a> 27:25, 135:128,<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a> 25:24,<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a> 256:243</td></tr><tr><th colspan="2" class="infobox-header notheme" style="background-color:palegoldenrod;"><a href="/en/Cent_(music)" title="Cent (music)" class="wl">Cents</a></th></tr><tr><th scope="row" class="infobox-label"><a href="/en/Equal_temperament#Twelve-tone_equal_temperament" title="Equal temperament" class="wl">Equal temperament</a></th><td class="infobox-data">100<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a></td></tr><tr><th scope="row" class="infobox-label"><a href="/en/Just_intonation" title="Just intonation" class="wl">Just intonation</a></th><td class="infobox-data">112,<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a> 105, 133, 92,<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a> 71,<a href="#cite_note-Duffin-1" style="counter-reset: mw-Ref 1;">[1]</a> 90</td></tr></tbody></table> <footer class='mobile-collapse-footer mobile-collapse-btn'>Close ▲</footer></div>
<figure class="mw-default-size wiki-thumb"><a href="/en/File:Minor_second_on_C.png" class="mw-file-description image media-thumb" data-hash="File:Minor_second_on_C.png"><img loading="lazy" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/ba/Minor_second_on_C.png/220px-Minor_second_on_C.png" decoding="async" data-file-width="542" data-file-height="252" data-file-type="bitmap" height="102" width="220" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/ba/Minor_second_on_C.png/330px-Minor_second_on_C.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/ba/Minor_second_on_C.png/440px-Minor_second_on_C.png 2x" alt="Minor_second_on_C.png"></a><figcaption>Minor second<div class='audio-player' title='Minor second on C.mid'><audio controls="" preload="none" height="32" width="220" resource="./File:Minor_second_on_C.mid"><source src="//upload.wikimedia.org/wikipedia/commons/8/8a/Minor_second_on_C.mid" type="audio/midi" data-title="Original ⧼timedmedia-midi⧽ file (0 bps)" data-shorttitle="⧼timedmedia-midi⧽ source"><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/8/8a/Minor_second_on_C.mid/Minor_second_on_C.mid.mp3" type="audio/mpeg" data-title="MP3" data-shorttitle="MP3"><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/8/8a/Minor_second_on_C.mid/Minor_second_on_C.mid.ogg" type="audio/ogg; codecs=&quot;vorbis&quot;" data-title="Ogg Vorbis" data-shorttitle="Ogg Vorbis"></audio></div></figcaption></figure>

In a 12-note approximately equally divided scale, any interval can be defined in terms of an appropriate number of semitones (e.g. a <a href="/en/Whole_tone" title="Whole tone" class="mw-redirect wl">whole tone</a> or major second is 2 semitones wide, a <a href="/en/Major_third" title="Major third" class="wl">major third</a> 4 semitones, and a <a href="/en/Perfect_fifth" title="Perfect fifth" class="wl">perfect fifth</a> 7 semitones.

In <a href="/en/Music_theory" title="Music theory" class="wl">music theory</a>, a distinction is made<a href="#cite_note-Wharram-6" style="counter-reset: mw-Ref 6;">[6]</a> between a diatonic semitone, or minor second (an interval encompassing two different <a href="/en/Staff_position" title="Staff position" class="mw-redirect wl">staff positions</a>, e.g. from C to D♭) and a chromatic semitone or augmented unison (an interval between two notes at the same staff position, e.g. from C to C♯). These are <a href="/en/Enharmonic" title="Enharmonic" class="wl">enharmonically equivalent</a> when <a href="/en/Equal_temperament" title="Equal temperament" class="wl">twelve-tone equal temperament</a> is used, but are not the same thing in <a href="/en/Meantone_temperament" title="Meantone temperament" class="wl">meantone temperament</a>, where the diatonic semitone is distinguished from and smaller than the chromatic semitone (augmented unison). See <a href="/en/Interval_(music)#Number" title="Interval (music)" class="wl">Interval (music) §&nbsp;Number</a> for more details about this terminology.

In <a href="/en/Twelve-tone_equal_temperament" title="Twelve-tone equal temperament" class="mw-redirect wl">twelve-tone equal temperament</a> all semitones are equal in size (100 cents). In other tuning systems, "semitone" refers to a family of intervals that may vary both in size and name. In <a href="/en/Pythagorean_tuning" title="Pythagorean tuning" class="wl">Pythagorean tuning</a>, seven semitones out of twelve are diatonic, with ratio 256:243 or 90.2 cents (<a href="#Pythagorean_tuning" target="_blank">Pythagorean limma</a>), and the other five are chromatic, with ratio 2187:2048 or 113.7 cents (<a href="#Pythagorean_tuning" target="_blank">Pythagorean apotome</a>); they differ by the <a href="/en/Pythagorean_comma" title="Pythagorean comma" class="wl">Pythagorean comma</a> of ratio 531441:524288 or 23.5 cents. In <a href="/en/Quarter-comma_meantone" title="Quarter-comma meantone" class="wl">quarter-comma meantone</a>, seven of them are diatonic, and 117.1 cents wide, while the other five are chromatic, and 76.0 cents wide; they differ by the lesser <a href="/en/Diesis" title="Diesis" class="wl">diesis</a> of ratio 128:125 or 41.1 cents. 12-tone scales tuned in <a href="/en/Just_intonation" title="Just intonation" class="wl">just intonation</a> typically define three or four kinds of semitones. For instance, <a href="/en/Five-limit_tuning#Size_of_intervals" title="Five-limit tuning" class="wl">Asymmetric</a> <a href="/en/Five-limit_tuning" title="Five-limit tuning" class="wl">five-limit tuning</a> yields chromatic semitones with ratios 25:24 (70.7 cents) and 135:128 (92.2 cents), and diatonic semitones with ratios 16:15 (111.7 cents) and 27:25 (133.2 cents). For further details, see <a href="#Just_intonation" title="Semitone" target="_blank">below</a>.

The condition of having semitones is called hemitonia; that of having no semitones is <a href="/en/Anhemitonic_scale" title="Anhemitonic scale" class="wl">anhemitonia</a>. A <a href="/en/Scale_(music)" title="Scale (music)" class="wl">musical scale</a> or <a href="/en/Chord_(music)" title="Chord (music)" class="wl">chord</a> containing semitones is called hemitonic; one without semitones is anhemitonic.

A semitone, also called a half step or a half tone, when sounded harmonically.
It is defined as the interval between two adjacent notes in a 12-tone scale. For example, C is adjacent to C♯; the interval between them is a semitone. In a 12-note approximately equally divided scale, any interval can be defined in terms of an appropriate number of semitones (e.g. a whole tone or major second is 2 semitones wide, a major third 4 semitones, and a perfect fifth 7 semitones. In music theory, a distinction is made between a diatonic semitone, or minor second and a chromatic semitone or augmented unison . These are enharmonically equivalent when twelve-tone equal temperament is used, but are not the same thing in meantone temperament, where the diatonic semitone is distinguished from and smaller than the chromatic semitone . See Interval § Number for more details about this terminology. 