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In music, sharp, dièse (from French), or diesis (from Greek)[a] means higher in pitch. More specifically, in musical notation, sharp means "higher in pitch by a semitone (half step)" ,and has an associated sharp symbol, ♯, which may be found in key signatures or as an accidental. Sharp is contrasted with flat, which refers to a lowering of pitch. Intonation may be flat, sharp, or both, successively or simultaneously.[clarification needed]
Under twelve-tone equal temperament, B♯, for instance, sounds the same as, or is enharmonically equivalent to, C natural (C♮), and E♯ is enharmonically equivalent to F♮. In other tuning systems, such enharmonic equivalences in general do not exist. To allow extended just intonation, composer Ben Johnston uses a sharp to indicate a note is raised 70.6 cents (ratio 25:24), or a flat to indicate a note is lowered 70.6 cents.
In tuning, 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 (assuming the lower one is properly pitched) is said to be sharp with respect to the other. Furthermore, the verb sharpen means "raise the frequency of a note, typically by a small musical interval".
Less often (in for instance microtonal music notation) one will encounter other sharps. A half sharp raises a note by a quarter tone = 50 cents ( Play (help·info)), and may be marked with various symbols including . A sharp and a half (or three-quarter-tone sharp) raises a note by three quarter tones = 150 cents ( Play (help·info)) and may be denoted .
Correctly drawing and printing the sharp sign
The sharp symbol (♯) may be confused with the number (hash or pound) sign (#). Both signs have two sets of parallel double-lines. However, a correctly drawn sharp sign must have two slanted parallel lines which rise from left to right, to avoid being obscured by the staff lines. The number sign, in contrast, has two compulsory 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 (according to typeface and writing style).
Order of sharps
The order of sharps in key signature notation is F♯, C♯, G♯, D♯, A♯, E♯, B♯, each extra sharp being added successively in the following sequence of major keys: C→G→D→A→E→B→F♯→C♯. (These are sometimes learned using an acrostic phrase as a mnemonic, for example Father Charles Goes Down And Ends Battle.) Similarly the order of flats is based on the same natural notes in reverse order: B♭, E♭, A♭, D♭, G♭, C♭, F♭ (Battle Ends And Down Goes Charles's Father.), encountered in the following series of major keys: C→F→B♭→E♭→A♭→D♭→G♭→C♭.
In the above progression, key C♯ (with seven sharps) may be more conveniently written as the harmonically equivalent key D♭ (with five flats), and likewise C♭ (with seven flats) written as B (with five sharps). Nonetheless, it is possible to extend the order of sharp keys yet further, through C♯→G♯→D♯→A♯→E♯→B♯→F→C, adding the double-sharped notes F, C, G, D, A, E and finally B, and similarly for the flat keys, but with progressively decreasing convenience and usage.
in Unicode, assigned sharp signs are:
- U+266F ♯ MUSIC SHARP SIGN (HTML
- U+1D12A 𝄪 MUSICAL SYMBOL DOUBLE SHARP (HTML
- U+1D130 𝄰 MUSICAL SYMBOL SHARP UP (HTML
- U+1D131 𝄱 MUSICAL SYMBOL SHARP DOWN (HTML
- U+1D132 𝄲 MUSICAL SYMBOL QUARTER TONE SHARP (HTML
- For the etymology of the words diese and diesis, see Diesis.
- John Fonville. "Ben Johnston's Extended Just Intonation – A Guide for Interpreters", p.109, Perspectives of New Music, Vol. 29, No. 2 (Summer, 1991), pp. 106-137. "...the 25/24 ratio is the sharp (♯) ratio...this raises a note approximately 70.6 cents."
- Ayrton, William (1827). The Harmonicon. V. Samuel Leigh. p. 47. ISBN 1276309457.
- Extremes of Conventional Music Notation.