Sharp (music): Difference between revisions

♯
♯
Sharp (music)
In Unicode	U+266F ♯ MUSIC SHARP SIGN (&sharp;)
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Different from	U+0023 # NUMBER SIGN; U+2317 ⌗ VIEWDATA SQUARE; U+22D5 ⋕ EQUAL AND PARALLEL TO; U+4E95 井 CJK UNIFIED IDEOGRAPH-4E95 (Jingtian)
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See also	U+266D ♭ MUSIC FLAT SIGN

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In music, sharp – eqv. dièse (from French) or diesis (from Greek $δίεσις$ )^[a] – means higher in pitch. The sharp symbol, ♯, indicates that the note to which the symbol is applied is played one semitone higher. The opposite of sharp is flat, indicating a lowering of pitch. The ♯ symbol derives from a square form of the letter b (see History of notation of accidentals for more information).

Examples

The sharp symbol is used in key signatures or as an accidental applied to a single note. The staff below has a key signature with three sharps (A major or its relative minor, F♯ minor). The sharp symbol placed on the note indicates that it is an A♯ instead of an A♮.

${ \omit Score.TimeSignature \relative c'' { \key a \major ais1 } }$

In twelve-tone equal temperament tuning (the predominant system of tuning in Western music), raising a note's pitch by a semitone results in a note that is enharmonically equivalent to the adjacent named note. In this system, A♯ and B♭ are considered to be equivalent. However, in the majority of tuning systems, this is not the case.

Variants

A double sharp () is indicated by the symbol and raises a note by two chromatic semitones. Historically, a double sharp was sometimes written , or .^[1]

${ \omit Score.TimeSignature \relative c'' { bisis1 } }$

A half sharp, or demisharp () raises a note by approximately a quarter tone. A sharp-and-a-half, three-quarter-tone sharp, or sesquisharp () raises a note by three quarter tones.

${ \omit Score.TimeSignature \relative c'' { dih1 eisih } }$

Although very uncommon, a triple sharp ( or ♯) can sometimes be found. It raises a note by three semitones or a whole tone and semitone.^[2]^[3]

${ \omit Score.TimeSignature \relative c'' { \tweak Accidental.stencil #ly:text-interface::print \tweak Accidental.text \markup { \concat { \sharp \doublesharp }} bis1 } }$

Key signature

${ \omit Score.TimeSignature { \key cis \major s16^"" } }$

The standard order in which sharps occur in a key signature is "F♯ C♯ G♯ D♯ A♯ E♯ B♯", with a maximum of 7.

In a key signature, sharps or flats are placed to the right of the clef. The pitches indicated apply in every measure and octave.

Number of sharps	Major key	Sharp notes	Minor key
0	C major	–	A minor
1	G major	F♯	E minor
2	D major	F♯, C♯	B minor
3	A major	F♯, C♯, G♯	F♯ minor
4	E major	F♯, C♯, G♯, D♯	C♯ minor
5	B major	F♯, C♯, G♯, D♯, A♯	G♯ minor
6	F♯ major	F♯, C♯, G♯, D♯, A♯, E♯	D♯ minor
7	C♯ major	F♯, C♯, G♯, D♯, A♯, E♯, B♯	A♯ minor

The order of sharps in key signature notation is F♯, C♯, G♯, D♯, A♯, E♯, B♯. Starting with no sharps or flats (C major), adding the first sharp (F♯) indicates G major, adding the next (C♯) indicates D major, and so on through the circle of fifths.

Some keys (such as C♯ major with seven sharps) may be written as an enharmonically equivalent key (D♭ major with five flats in this case). In rare cases, the sharp keys may be extended further, G♯ → D♯ → A♯ → E♯ → B♯ → F → C, requiring double sharps in the key signature: F, C, G, D, A, E, B. These are called theoretical key signatures. This principle applies similarly to the flat keys.

Temporary accidental

When used as a temporary accidental sign, sharps apply to the note on which they are placed, and to all subsequent similar notes in the same measure and octave. the sharp symbol is placed to the left of the note head.

${ \omit Score.TimeSignature \relative c'' { bis1 } }$

Temporary accidentals apply to the note on which they are placed, and to subsequent similar notes in the same measure. In modern notation they do not apply to notes in other octaves or measure, but this was not always the convention. If a sharp is used as an accidental, it can be cancelled on a subsequent similar note in the staff, measure and octave by using a flat (♭) or a natural (♮).

${ \omit Score.TimeSignature \key c \major \time 4/4 bis'2 bes' bis' b'}$

Unicode

In Unicode, assigned sharp signs are as follows:

U+266F ♯ MUSIC SHARP SIGN (&sharp;)
U+1D12A 𝄪 MUSICAL SYMBOL DOUBLE SHARP
U+1D130 𝄰 MUSICAL SYMBOL SHARP UP
U+1D131 𝄱 MUSICAL SYMBOL SHARP DOWN
U+1D132 𝄲 MUSICAL SYMBOL QUARTER TONE SHARP

Other notation and usage

The sharp symbol (♯) resembles the number (hash) sign (#), in that both have two intersecting sets of parallel double lines. While the number sign may have a pair of horizontal lines, the sharp sign has a pair of slanted lines that rise from left to right instead, to avoid obscuring the staff lines. The other set of parallel lines are vertical in the sharp sign, while the number sign (#) may have slanted lines instead.^{[citation needed]} It is also etymologically independent from the number sign. Likewise, while the double-sharp sign resembles a bold-face lower-case x it needs to be typographically distinct.
Historically, lowering a double sharp to a single sharp could be notated using a natural and sharp sign (♮♯) or vice-versa (♯♮) instead of the conventional sharp sign (♯), but the natural sign is often omitted in modern notation. The similar principle of the natural sign notation can apply when canceling a triple sharp or beyond.^[4] The combination ♮♯ can be also written when changing a flat to a sharp.^[5]

${ \omit Score.TimeSignature \relative c'' { bisis2 bis \accidentalStyle modern bisis2 bis } }$

To allow extended just intonation, composer Ben Johnston uses a sharp to indicate a note is raised 70.6 cents (ratio 25:24).^[6]
In environments where the symbol is not supported, or in specific text notation, a double sharp is sometimes written using two single sharp signs (♯♯) or a lower-case letter x. Likewise, a triple sharp can be written as ♯♯♯.

Notes

^ For the etymology of the words dièse, diesis, and $δίεσις$ , see diesis.

References

^ Chisholm, Hugh, ed. (1911). "Musical Notation" . Encyclopædia Britannica. Vol. 19 (11th ed.). Cambridge University Press. p. 87.
^ Ayrton, William (1827). The Harmonicon. Vol. V. Samuel Leigh. p. 47. ISBN 1276309457.
^ Byrd, Donald (2018). "Extremes of conventional music notation" (academic pers. page). Bloomington, IN: University of Indiana.
^ Max Reger: Clarinet Sonata No.2 (Complete Score), pp. 33.: Scores at the International Music Score Library Project
^ Chopin: Études No. 9, Op.10 (C.F. Peters), pp. 429.: Scores at the International Music Score Library Project
^ Fonville, J. (Summer 1991). "Ben Johnston's extended just intonation – a guide for interpreters". Perspectives of New Music. 29 (2): 106–137, esp. 109. doi:10.2307/833435. JSTOR 833435. ... the ⁠25/ 24 ⁠ ratio is the sharp (♯) ratio ... this raises a note approximately 70.6 cents.

[1] For the etymology of the words dièse, diesis, and $δίεσις$ , see diesis.

[2] Chisholm, Hugh, ed. (1911). "Musical Notation" . Encyclopædia Britannica. Vol. 19 (11th ed.). Cambridge University Press. p. 87.

[3] Ayrton, William (1827). The Harmonicon. Vol. V. Samuel Leigh. p. 47. ISBN 1276309457.

[4] Byrd, Donald (2018). "Extremes of conventional music notation" (academic pers. page). Bloomington, IN: University of Indiana.

[5] Max Reger: Clarinet Sonata No.2 (Complete Score), pp. 33.: Scores at the International Music Score Library Project

[6] Chopin: Études No. 9, Op.10 (C.F. Peters), pp. 429.: Scores at the International Music Score Library Project

[7] Fonville, J. (Summer 1991). "Ben Johnston's extended just intonation – a guide for interpreters". Perspectives of New Music. 29 (2): 106–137, esp. 109. doi:10.2307/833435. JSTOR 833435. ... the ⁠25/ 24 ⁠ ratio is the sharp (♯) ratio ... this raises a note approximately 70.6 cents.

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@@ Line 1: / Line 1: @@
 {{short description|Accidental raising the pitch of a note by one chromatic semitone (♯)}}
 {{About||the use of the sharp sign in mathematics|Musical isomorphism|the use of the sharp sign in computational complexity theory|♯P}}
-{{redirect-distinguish-text|♯|the [[number sign|#]] or the [[well-field system]]}}
+{{redirect-distinguish-text|♯|the [[number sign]] (#)}}
+{{for|the Japanese electronics company|Sharp Corporation}}
-In [[music]], '''sharp''', '''{{lang|fr|dièse}}''' (from [[French language|French]]), or '''{{lang|he|diesis}}''' (from [[Greek language|Greek]]){{efn|
+{{Infobox symbol
-For the etymology of the words {{lang|fr|dièse}} and ''diesis'', see [[Diesis]].
+ |mark=<nowiki>♯</nowiki>
+ |unicode={{unichar |266F |Music sharp sign |html=}}
+ |see also={{unichar|266D |nlink=Flat (music)}}
+ |different from={{unichar |0023 |nlink=number sign }}<br/>{{unichar |2317 |nlink=viewdata square}}<br/>{{unichar |22D5 |nlink=Parallel (geometry)#Symbol}}<br/>{{unichar |4E95 |note=[[Jingtian]]}}
 }}
+In [[music]], '''sharp''' – eqv. '''{{lang|fr|dièse}}''' (from [[French language|French]]) or '''{{lang|he|diesis}}''' (from [[Greek language|Greek]]  {{math|δίεσις}}){{efn|
-means, "higher in [[pitch (music)|pitch]]". More specifically, in [[musical notation]], sharp means "higher in pitch by one [[semitone]] (half step)". A sharp is the opposite of a [[Flat (music)|flat]], a lowering of pitch. The ♯ symbol itself is conjectured to be a condensed form of [[German language|German]] ligature {{mvar|ſch}} (for [[wikt:scharf#German|''scharf'']]) or the symbol {{math|ƀ}} (for "cancelled flat").
+For the etymology of the words {{lang|fr|dièse}}, ''diesis'', and {{math|δίεσις}}, ''see'' [[diesis]].
+}} – means higher in [[pitch (music)|pitch]]. The sharp symbol, {{music|#}}, indicates that the [[note (music)|note]] to which the symbol is applied is played one [[semitone]] higher. The opposite of sharp is [[flat (music)|flat]], indicating a lowering of pitch.  The {{music|#}} symbol derives from a square form of the letter ''b'' (see [[Accidental (music)#History of notation|History of notation of accidentals]] for more information).
-In [[Intonation (music)|intonation]], ''sharp'' can also mean "slightly higher in pitch" (by some unspecified amount). If two simultaneous notes are ''slightly'' out-of-tune, the higher-pitched one is ''sharp'', assuming the lower one is properly pitched; regardless of proper pitch, the higher note is ''sharp'' with respect to the lower. The verb ''sharpen'' means to raise the pitch of a note by a small amount, typically less than a semitone.
 == Examples ==
-A sharp symbol, {{Music|sharp}}, is used in [[key signature]]s or as an [[accidental (music)|accidental]]. For instance, the music below has a key signature with three sharps (indicating either [[A major]] or [[F-sharp minor|F{{Music|sharp}} minor]], the [[Relative key|relative minor]]) and the note, [[A♯ (musical note)|'''A'''{{Music|sharp}}]], has a sharp accidental.
+The sharp symbol is used in [[key signature]]s or as an [[accidental (music)|accidental]] applied to a single note. The staff below has a key signature with three sharps ([[A major]] or its [[relative key|relative minor]], [[F-sharp minor|F{{music|#}} minor]]). The sharp symbol placed on the note indicates that it is an A{{music|#}} instead of an A{{music|N}}.
-:<div style="background-color: white;"><score> {
+:<score> {
-\override Score.TimeSignature #'stencil = ##f
+\omit Score.TimeSignature \relative c'' { \key a \major ais1 } }
+</score>
-\relative c'' {
+In [[twelve-tone equal temperament]] tuning (the predominant system of tuning in Western music), raising a note's pitch by a semitone results in a note that is [[Enharmonic|enharmonically equivalent]] to the adjacent named note. In this system, A{{music|#}} and B{{Music|flat}} are considered to be equivalent. However, in the majority of [[Musical tuning#Tuning systems|tuning system]]s, this is not the case.
-  \clef treble \key a \major \time 4/4 ais1
-} }
-</score></div>
-Under [[twelve-tone equal temperament]], the pitch '''B'''{{music|#}}, for instance, sounds the same as, or is [[enharmonically equivalent]] to, '''C'''&nbsp;[[natural sign|natural]] ('''C'''{{music|natural}}), and '''E'''{{music|#}} is enharmonically equivalent to '''F'''{{music|natural}}. In other [[Musical tuning#Tuning systems|tuning system]]s, such enharmonic equivalences in general do not exist: In nearly every system ''except'' the [[Equal Temperament]]s, differently notated pitches (e.g. '''F'''{{music|x#}} and '''A'''{{music|b}}) are distinct.{{efn|
-The conventions of western musical notation developed when unequal [[meantone temperament]]s and [[well temperament]]s were the most widely used tunings, and [[12 equal temperament|equal temperament]] was still a theoretical proposal. For time orientation, and for example, [[J.S. Bach]]'s ''[[The Well-Tempered Klavier]]'' (1722) appears to have been intended as a demonstration-piece for music writen to exploit the differences in tonality in the various [[well temperament]]s, which had been recently introduced in his time, whereas equal temperament came into common practice long after his death. Bach himself appears to have most often used something close to a {{sfrac| 1 |6}}&nbsp;[[Pythagorean comma|comma]] [[meantone temperament]]; the various meantone temperaments were the prevailing systems at that time, and lingered in use for tuning [[organ (music)|pipe organs]] into the early 20th&nbsp;century. Bach's choral notation is essentially the same as in current use, and remains appropriate for all tuning systems in use during his time, and the later adopted equal temperament. The circumspect continued adherence to the same conventions Bach and his contemporaries observed for accidentals, developed prior to the near-universal use of [[equal temperament]], ensures that music that is harmonically consonant in any one tuning system remains (very nearly) concordant any other tuning system. That is, as long as the false equivalences of invalid [[enharmonic]] substitutions – which create [[wolf tone]]s – are never used (like keying '''F''' to replace an unavailable '''E'''{{music|#}}, or substituting '''F'''{{music|#}} for '''G'''{{music|b}} in any unequal meantone tuning).
-}}
-To allow extended [[just intonation]], composer [[Ben Johnston (composer)|Ben Johnston]] uses a sharp to indicate a note is raised 70.6&nbsp;[[cent (music)|cent]]s (ratio 25:24), or a flat to indicate a note is lowered 70.6&nbsp;cents.<ref>{{cite journal |last=Fonville |first=J. |author-link=John Fonville |date=Summer 1991 |title=Ben Johnston's extended Just Intonation – a guide for interpreters |journal=[[Perspectives of New Music]] |volume=29 |number=2 |pages=106–137, esp.&nbsp;109 |doi=10.2307/833435 |jstor=833435 |quote=...&nbsp;the [[just chromatic semitone|{{sfrac|25| 24 }} ratio]] is the sharp ({{music|#}}) ratio ... this raises a note approximately 70.6&nbsp;cents.}}</ref>
 == Variants ==
-'''Double sharps''' are indicated by the symbol {{Music|x}} and raise a note by two [[semitone]]s, or one [[Major second|whole tone]]. It should not be confused with a [[ghost note]] which is notated with "×".
+A '''double sharp''' ({{music|x}}) is indicated by the symbol {{music|x}} and raises a note by two chromatic [[semitone]]s. Historically, a double sharp was sometimes written [[File:EB1911 - Musical Notation - double sharp 1.png|13px]], [[File:EB1911 - Musical Notation - double sharp 2.png|18px]]  or [[File:EB1911 - Musical Notation - double sharp 3.png|16px]].<ref>
+{{cite EB1911|wstitle=Musical Notation|volume=19|page=87}}
-:<score> {
+</ref>
-\override Score.TimeSignature #'stencil = ##f
-\relative c'' {
+:<score> { \omit Score.TimeSignature \relative c'' { bisis1 } }</score>
-  \clef treble \time 1/1 bisis1
-} }</score>
-Less often (in for instance [[microtonal music]] [[Accidental (music)#Microtonal notation|notation]]) a score indicates other types of sharps. A '''half sharp''', or '''demisharp''' raises a note by a [[quarter tone]] = 50&nbsp;[[cent (music)|cents]] ({{audio|Quarter tone on C.mid|Play}}), and may be marked with various symbols including {{music|t}}. A '''sharp-and-a-half''', '''three-quarter-tone sharp''', or '''sesquisharp''', raises a note by three quarter tones = 150&nbsp;cents ({{audio|Neutral second on C.mid|Play}}) and may be denoted {{music|#t}}.
+A '''half sharp''', or '''demisharp''' ({{music|t}}) raises a note by approximately a [[quarter tone]]. A '''sharp-and-a-half''', '''three-quarter-tone sharp''', or '''sesquisharp''' ({{music|#t}}) raises a note by three quarter tones.
+:<score>{
-:<div style="background-color: white;">'''<score> {
-\override Score.TimeSignature #'stencil = ##f
+\omit Score.TimeSignature \relative c'' { dih1 eisih } }</score>
-\relative c'' {
-  \clef treble \time 4/4 dih1 eisih
-} }
-</score>'''</div>
-Although very uncommon, a '''triple sharp''' ({{Music|#x}}) can sometimes be found. It raises a note by three semitones or a whole tone and a semitone.<ref>{{cite book |last=Ayrton |first=William |year=1827 |title=The Harmonicon |publisher=Samuel Leigh |volume=V |page=47 |isbn=1276309457 |url=https://books.google.com/books?id=88IJAQAAMAAJ&q=%22double+sharp+major%22+scale&pg=PA47}}</ref><ref>{{cite web |last=Byrd |first=Donald |year=2018 |title=Extremes of conventional music notation |place=Bloomington, IN |publisher=[[University of Indiana]] |url=https://homes.luddy.indiana.edu/donbyrd/CMNExtremes.htm }}</ref>
+Although very uncommon, a '''triple sharp''' ({{Music|#x}} or {{Music|x}}{{Music|#}}) can sometimes be found. It raises a note by three [[semitones]] or a [[whole tone]] and [[semitone]].<ref>
+{{cite book |last=Ayrton |first=William |url=https://books.google.com/books?id=88IJAQAAMAAJ&q=%22double+sharp+major%22+scale&pg=PA47 |title=The Harmonicon |publisher=Samuel Leigh |year=1827 |isbn=1276309457 |volume=V |page=47}}
+</ref><ref>
+{{cite web |last=Byrd |first=Donald |year=2018 |title=Extremes of conventional music notation |url=https://homes.luddy.indiana.edu/donbyrd/CMNExtremes.htm |publisher=[[University of Indiana]] |place=Bloomington, IN |type=academic pers. page}}
+</ref>
 :<score> {
-\override Score.TimeSignature #'stencil = ##f
+\omit Score.TimeSignature \relative c'' {
+  \tweak Accidental.stencil #ly:text-interface::print \tweak Accidental.text \markup { \concat { \sharp \doublesharp }} bis1
-\relative c'' {
-  \clef treble \time 1/1 \tweak Accidental.stencil #ly:text-interface::print \tweak Accidental.text \markup { \concat { \sharp \doublesharp }} bis1
 } }</score>
+== Key signature ==
-And although it could make the music generally impractical to read, theoretically, a '''quadruple sharp'''<ref>It raises a note by four semitones or two whole tones.</ref> and beyond could be also considered.<ref><Ex. Faerie's Aire and Death Waltz></ref>
+{{Image frame|content=<score>{ \omit Score.TimeSignature { \key cis \major s16^"" } }</score>|width=200|caption=The standard order in which sharps occur in a key signature is "F♯ C♯ G♯ D♯ A♯ E♯ B♯", with a maximum of 7.}}In a key signature, [[Sharp (music)#top|sharps]] or [[Flat (music)|flats]] are placed to the right of the clef. The pitches indicated apply in every measure and octave.<!--Please do not change the sharp signs to number (#) signs.-->
+{| class="wikitable"
-Historically, in order to lower a double sharp to a sharp, it would be denoted as a [[Double natural|♮♯]] or [[Double natural|♯♮]]. In modern notation the [[Natural (music)|natural]] sign has been often omitted. Theoretically, the same principle could be considered when canceling the symbol of a triple sharp or beyond.<ref>{{IMSLP|work=2 Clarinet Sonatas, Op.49 (Reger, Max)|cname=Max Reger: Clarinet Sonata No.2 (Complete Score), pp. 33.}}</ref><ref>A ♮♯ can be also written when changing a flat to a sharp. {{IMSLP|work=Études, Op.10 (Chopin, Frédéric)|cname=Chopin: Études No. 9, Op.10 (C.F. Peters), pp. 429.}}</ref>
+!Number
-:<score> {
+of sharps
-\override Score.TimeSignature #'stencil = ##f
+!Major key
-\relative c'' {
+!Sharp notes
-  \clef treble \time 4/4 bisis2 bis \accidentalStyle modern bisis2 bis
+!Minor key
-} }
+|-
-</score>
+|0
+|[[C major]]
+|–
+|[[A minor]]
+|-
+|1
+|[[G major]]
+|F{{music|#}}
+|[[E minor]]
+|-
+|2
+|[[D major]]
+|F{{music|#}}, C{{music|#}}
+|[[B minor]]
+|-
+|3
+|[[A major]]
+|F{{music|#}}, C{{music|#}}, G{{music|#}}
+|[[F-sharp minor|F{{music|#}} minor]]
+|-
+|4
+|[[E major]]
+|F{{music|#}}, C{{music|#}}, G{{music|#}}, D{{music|#}}
+|[[C-sharp minor|C{{music|#}} minor]]
+|-
+|5
+|[[B major]]
+|F{{music|#}}, C{{music|#}}, G{{music|#}}, D{{music|#}}, A{{music|#}}
+|[[G-sharp minor|G{{music|#}} minor]]
+|-
+|6
+|[[F-sharp major|F{{music|#}} major]]
+|F{{music|#}}, C{{music|#}}, G{{music|#}}, D{{music|#}}, A{{music|#}}, E{{music|#}}
+|[[D-sharp minor|D{{music|#}} minor]]
+|-
+|7
+|[[C-sharp major|C{{music|#}} major]]
+|F{{music|#}}, C{{music|#}}, G{{music|#}}, D{{music|#}}, A{{music|#}}, E{{music|#}}, B{{music|#}}
+|[[A-sharp minor|A{{music|#}} minor]]
+|}
+The order of sharps in [[key signature]] [[Modern musical symbols|notation]] is '''F'''{{music|#}}, '''C'''{{music|#}}, '''G'''{{music|#}}, '''D'''{{music|#}}, '''A'''{{music|#}}, '''E'''{{music|#}}, '''B'''{{music|#}}. Starting with no sharps or flats (C major), adding the first sharp (F{{music|#}}) indicates G major, adding the next (C{{music|#}}) indicates D major, and so on through the [[circle of fifths]].
-==Order of sharps==
-{{Main|Circle of fifths}}
-The order of sharps in [[key signature]] [[Modern musical symbols|notation]] is '''F'''{{music|sharp}}, '''C'''{{music|sharp}}, '''G'''{{music|sharp}}, '''D'''{{music|sharp}}, '''A'''{{music|sharp}}, '''E'''{{music|sharp}}, '''B'''{{music|sharp}}, each extra sharp being added successively in the following sequence of major keys: '''C→G→D→A→E→B→F'''{{music|sharp}}→'''C'''{{music|sharp}}. (These are sometimes learned using an [[acrostic]] phrase as a [[mnemonic]], for example: &nbsp;
-'''F'''ather '''C'''an '''G'''rab '''D'''ogs '''A'''t '''E'''venings '''B'''est &nbsp; or &nbsp;
-'''F'''ather '''C'''harles '''G'''oes '''D'''own '''A'''nd '''E'''nds '''B'''attle &nbsp; or &nbsp;
-'''F'''ather '''C'''hristmas '''G'''ave '''D'''ad '''A'''n '''E'''lectric '''B'''lanket &nbsp; or &nbsp;
-'''F'''at '''C'''ows '''G'''o '''D'''own '''A'''nd '''E'''at '''B'''uttercups &nbsp; or &nbsp;
-'''F'''ather '''C'''hristmas '''G'''oes '''D'''own '''A'''ll '''E'''scalators '''B'''ackwards.)
-Similarly the order of flats is based on the same natural notes in reverse order: '''B'''{{music|b}}, '''E'''{{music|b}}, '''A'''{{music|b}}, '''D'''{{music|b}}, '''G'''{{music|b}}, '''C'''{{music|b}}, '''F'''{{music|b}}
+Some keys (such as C{{music|#}} major with seven sharps) may be written as an enharmonically equivalent key (D{{music|b}} major with five flats in this case). In rare cases, the sharp keys may be extended further, '''G'''{{music|#}} → '''D'''{{music|#}} → '''A'''{{music|#}} → '''E'''{{music|#}} → '''B'''{{music|#}} → '''F'''{{music|x}} → '''C'''{{music|x}}, requiring double sharps in the key signature: '''F'''{{music|x}}, '''C'''{{music|x}}, '''G'''{{music|x}}, '''D'''{{music|x}}, '''A'''{{music|x}}, '''E'''{{music|x}}, '''B'''{{music|x}}. These are called ''[[theoretical key]] signatures''. This principle applies similarly to the flat keys.
-'''B'''attle '''E'''nds '''A'''nd '''D'''own '''G'''oes '''C'''harles's '''F'''ather or '''B'''lanket '''E'''xploded '''A'''nd '''D'''ad '''G'''ot '''C'''old '''F'''eet, encountered in the following series of major keys: '''C→F→B'''{{music|b}}→'''E'''{{music|b}}→'''A'''{{music|b}}→'''D'''{{music|b}}→'''G'''{{music|b}}→'''C'''{{music|b}}.
+== Temporary accidental ==
-In the above progression, the key of '''C'''{{music|sharp}} major (with seven sharps) may be more conveniently written as the harmonically equivalent key '''D'''{{music|b}} major (with five flats), and likewise C{{music|b}} major (with seven flats) may be more conveniently written as '''B''' major (with five sharps). Nonetheless, it is possible to extend the order of sharp keys yet further, through '''C'''{{music|sharp}}→'''G'''{{music|sharp}}→'''D'''{{music|sharp}}→'''A'''{{music|sharp}}→'''E'''{{music|sharp}}→'''B'''{{music|sharp}}→'''F'''{{music|x}}→'''C'''{{music|x}}, adding the double-sharped notes '''F'''{{music|x}}, '''C'''{{music|x}}, '''G'''{{music|x}}, '''D'''{{music|x}}, '''A'''{{music|x}}, '''E'''{{music|x}}, and finally '''B'''{{music|x}}, and similarly for the flat keys from C{{music|b}} major to '''C'''{{music|bb}} major, but with progressively decreasing convenience and usage.
+When used as a temporary [[Accidental (music)|accidental]] sign, [[Sharp (music)#top|sharps]] apply to the note on which they are placed, and to all subsequent similar notes in the same measure and octave. the sharp symbol is placed to the left of the note head.
+<score> { \omit Score.TimeSignature \relative c'' { bis1 } }</score>
-==Correctly drawing and displaying the sharp sign==
-The sharp symbol ({{music|sharp}}) resembles the [[number sign|number (hash) sign]] (#). Both signs have two sets of parallel double-lines. However, a correctly drawn sharp sign has two slanted parallel lines that rise from left to right, to avoid obscuring the staff lines. The number sign, in contrast, has two completely horizontal strokes in this place. In addition, while the sharp also always has two perfectly vertical lines, the number sign (#) may or may not contain perfectly vertical lines (depending on typeface and writing style).{{citation needed|date=September 2012}}
+Temporary accidentals apply to the note on which they are placed, and to subsequent similar notes in the same measure. In modern notation they do not apply to notes in other octaves or measure, but this was not always the convention. If a sharp is used as an accidental, it can be cancelled on a subsequent similar note in the staff, measure and octave by using a [[Flat (music)|flat]] ({{music|b}}) or a [[Natural (music)|natural]] ({{music|N}}).
-<!-- This section should have info about distinguishing the double sharp from the letter x. Please discuss this HTML comment on the talk page if there are any objections. -->
-Likewise, although the double-sharp sign {{music|x}} resembles a bold-face lower-case [[letter X|'''x''']] it also needs to be presented in a way that makes the two typographically distinct.
+<score>{ \omit Score.TimeSignature \key c \major \time 4/4 bis'2 bes' bis' b'}</score>
-===Unicode===
+== Unicode ==
 In [[Unicode]], assigned sharp signs are as follows:
 * {{unichar|266F|MUSIC SHARP SIGN|html=}}
@@ Line 85: / Line 112: @@
 * {{unichar|1d131|MUSICAL SYMBOL SHARP DOWN|html=}}
 * {{unichar|1d132|MUSICAL SYMBOL QUARTER TONE SHARP|html=}}
+== Other notation and usage ==
+* The [[Sharp (music)#top|sharp]] symbol ({{music|#}}) resembles the [[number sign|number (hash) sign]] (#), in that both have two intersecting sets of parallel double lines. While the number sign may have a pair of horizontal lines, the sharp sign has a pair of slanted lines that rise from left to right instead, to avoid obscuring the staff lines. The other set of parallel lines are vertical in the sharp sign, while the number sign (#) may have slanted lines instead.{{citation needed|date=September 2012}} It is also etymologically independent from the number sign.<!-- This section should have info about distinguishing the double sharp from the letter x. Please discuss this HTML comment on the talk page if there are any objections. --> Likewise, while the double-sharp sign {{music|x}} resembles a bold-face lower-case [[letter X|'''x''']] it needs to be typographically distinct.
+* Historically, lowering a [[Sharp (music)#Variants|double sharp]] to a single sharp could be notated using a [[Natural (music)|natural]] and sharp sign ([[♮♯]]) or vice-versa ([[♯♮]]) instead of the conventional sharp sign (♯), but the [[Natural (music)|natural]] sign is often omitted in modern notation. The similar principle of the [[Natural (music)|natural]] sign notation can apply when canceling a [[Sharp (music)#Variants|triple sharp]] or beyond.<ref>{{IMSLP|work=2 Clarinet Sonatas, Op.49 (Reger, Max)|cname=Max Reger: Clarinet Sonata No.2 (Complete Score), pp. 33.}}</ref> The combination {{music|N}}{{music|#}} can be also written when changing a [[flat (music)|flat]] to a [[Sharp (music)#top|sharp]].<ref>{{IMSLP|work=Études, Op.10 (Chopin, Frédéric)|cname=Chopin: Études No. 9, Op.10 (C.F. Peters), pp. 429.}}</ref>
+:<score> { \omit Score.TimeSignature \relative c'' {
+  bisis2 bis \accidentalStyle modern bisis2 bis } }
+</score>
+* To allow extended [[just intonation]], composer [[Ben Johnston (composer)|Ben Johnston]] uses a sharp to indicate a note is raised 70.6&nbsp;[[cent (music)|cent]]s (ratio 25:24).<ref>
+{{cite journal |last=Fonville |first=J. |author-link=John Fonville |date=Summer 1991 |title=Ben Johnston's extended just intonation – a guide for interpreters |journal=[[Perspectives of New Music]] |volume=29 |pages=106–137, esp.&nbsp;109 |doi=10.2307/833435 |jstor=833435 |quote=...&nbsp;the [[just chromatic semitone|{{sfrac| 25 | 24 }} ratio]] is the sharp ({{music|#}}) ratio ... this raises a note approximately 70.6&nbsp;cents. |number=2}}</ref>
+* In environments where the {{music|x}} symbol is not supported, or in specific text notation, a '''[[Sharp (music)#Variants|double sharp]]''' is sometimes written using two single sharp signs ({{music|#}}{{music|#}}) or a lower-case letter x. Likewise, a '''[[Sharp (music)#Variants|triple sharp]]''' can be written as {{music|#}}{{music|#}}{{music|#}}.
-==See also==
+== See also ==
 * [[Flat (music)]]
 * [[Electronic tuner]]
 {{portal|Music}}
-==Notes==
+== Notes ==
 {{notelist}}
-==References==
+== References ==
 {{reflist|25em}}

v t e Musical notation
Staff	8^va 15^ma Abbreviation Bar Clef Da capo Dal segno Key signature Ledger line Mode Ossia Scale Rehearsal letter Repeat sign Tempo Time signature Transposition Transposing instrument
Musical notes	Accidental flat natural sharp Cue note Dotted note Grace note Note value beam Notehead stem Pitch Rest Tacet Tuplet Tremolo Interval Helmholtz pitch notation Letter notation Scientific pitch notation
Articulation	Accent Caesura Damping Dynamics Fermata Fingering Legato Marcato Ornament Appoggiatura Glissando Grace note Mordent Slide Trill Portato Slur Staccato Tenuto Tie Tonguing
Sheet music	History of music publishing Music engraving Music publisher Scorewriter
Other systems	Braille music Chord chart Chord diagram Eye music Figured bass Graphic notation Lead sheet Nashville Number System Numbered musical notation Klavarskribo Tablature Parsons Percussion notation Simplified Ancient Greek Chinese Ekphonetic Gamelan Kunkunshi Neume Swaralipi Shakuhachi Znamenny
Related	Mensural notation Music stand Perfect pitch Sight-reading Transcription
List of musical symbols Category:Musical notation