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In standard music notation, the order in which sharps or flats appear in key signatures is uniform, following the circle of fifths: F ♯, C ♯, G ♯, D ♯, A ♯, E ♯, B ♯, and B ♭, E ♭, A ♭, D ♭, G ♭, C ♭, F ♭. Key signatures indicate that this applies to the section of music that follows, showing the reader which key the music is in, and making it unnecessary to apply accidentals to individual notes.
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Starting the pattern on D, for example, yields D-E-F ♯-G-A-B-C ♯-D, so the key signature for D major has two sharps-F ♯ and C ♯. These raised or lowered notes form the key signature. Starting on any other note requires that at least one of these notes be changed (raised or lowered) to preserve the major scale pattern. There are no sharps or flats in this scale, so the key signature for C has no sharps or flats in it. Starting on C, this yields C-D-E-F-G-A-B-C (a C-major scale). With any note as a starting point, a certain series of intervals produces a major scale: whole step, whole, half, whole, whole, whole, half. B major scale: key signature accidentals not needed Music was sometimes notated with a key signature that did not match its key in this way-this can be seen in some Baroque pieces, or transcriptions of traditional modal folk tunes. These contain either flats or sharps, but not both, and the different key signatures add flats or sharps according to the order shown in the circle of fifths.Įach major and minor key has an associated key signature, showing up to seven flats or seven sharps, that indicates the notes used in its scale. Most of this article addresses key signatures that represent the diatonic keys of Western music. This convention was not universal until the late Baroque and early Classical period-music published in the 1720s and 1730s may have key signatures showing sharps or flats in both octaves for notes which fall within the staff. Each symbol applies to all notes in the same pitch class-for example, a flat on the third line of the treble staff (as in the diagram) indicates that all notes appearing as Bs are played as B-flats. This applies through the end of the piece or until another key signature is indicated. In a key signature, a sharp or flat symbol on a line or space of the staff indicates that the note represented by that line or space is to be played a semitone higher (sharp) or lower (flat) than it would otherwise be played. If the piece contains a section in a different key, the new key signature is placed at the beginning of that section. The initial key signature in a piece is placed immediately after the clef at the beginning of the first line. In Western musical notation, a key signature is a set of sharp ( ♯), flat ( ♭), or rarely, natural ( ♮) symbols placed on the staff at the beginning of a section of music. Key signature showing F ♯ and C ♯ (the key of D major or B minor)
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