Overview
The term sharp in Western music denotes a pitch that is higher than the written reference note. In standard staff notation a sharp sign indicates that a note is to be raised by one semitone (a half step) from its natural pitch. This operation affects pitch spelling, harmonic analysis and performance practice: the choice to spell a raised pitch as, for example, G sharp rather than A flat often reflects the intended harmonic function and voice-leading.
Symbols and common variants
The most common accidental is the single sharp (♯), used both as an accidental before a note and in key signatures. Other variants appear for specific theoretical or practical reasons:
- Single sharp (♯) — raises a note by one semitone and is used in accidentals and key signatures. See a general discussion of staff notation at musical notation.
- Double sharp — indicates a raise of two semitones (a whole step). This is written with a distinct symbol and is used when notation requires preserving correct intervallic spelling; see double-sharp references for examples.
- Microtonal accidentals — in contemporary and non-Western contexts composers sometimes use half-sharps, quarter-sharps or three-quarter sharps to indicate pitches between the standard semitones.
- Triple sharp — exceptionally rare; used only in some modern editions to indicate a raise of three semitones and usually avoided unless required by the theoretical context.
Symbols illustration
Printed and digital editions may show the basic symbols differently depending on font and engraving practice. For illustration purposes the standard sharp and its extended forms are sometimes presented graphically; typical editorial resources and reference fonts discuss these forms in more detail. Representative glyphs or editorial images appear in specialist sources: 
Enharmonic equivalents and temperament
Under twelve-tone equal temperament many raised notes are enharmonically equivalent to other named pitches. For example, B sharp is enharmonically equivalent to C natural, and G sharp to A flat, in equal temperament. However, in historical temperaments or in contexts where precise intonation is required, an indicated sharp may not coincide exactly with the pitch of its enharmonic alternative; tuning and temperament affect the size of intervals and therefore the exact frequency of a "sharp" note. See materials on enharmonic equivalence and temperaments for more detail.
Key signatures and the circle of fifths
Sharps appear systematically in key signatures. The order and number of sharps for major and minor keys follow the sequence shown by the circle of fifths, a pedagogical tool that helps readers predict which notes are sharped in any given key. Composers and editors use key signatures and accidentals together to indicate long-term pitch alterations and local deviations.
Tuning, intonation and performance use
Outside notation, "sharp" commonly describes a pitch that is slightly higher than intended: a player or singer may be described as "sharp" if they produce sound above the target pitch. In ensemble playing, musicians listen and adjust to avoid sounding sharp relative to a reference pitch. Instruments with fixed tuning, such as keyboard instruments, cannot be adjusted by performers in real time, so the concept of a note being "sharp" there often refers to a mismatch with a different instrument or an incorrect tuning reference.
Digital encoding and typography
The sharp sign is encoded in character sets and may appear differently across fonts and platforms. Unicode assigns the standard sharp to a specific code point and related symbols for double sharps or musical symbols are encoded separately; consult general references on character encoding at Unicode. For basic interval definitions and the term for a half step see semitone and related entries. Practical notation-engraving guides and theory texts explain when a sharp is preferred for theoretical clarity versus when an enharmonic spelling may be simpler; see introductory materials at accidentals.
Further reading
Students seeking to learn how sharps operate in harmony and melody will find value in beginner and intermediate music theory textbooks, notation manuals, and interactive tutorials. Overviews and exercises on key signatures, accidental rules, and the circle of fifths are commonly available in pedagogical resources and online tutorials that treat these topics in context; a useful starting point for applied practice is an introductory guide to the circle of fifths combined with notation references such as musical notation and specific entries on enharmonic equivalence.