Flat (music)

In music, flat (Italian bemolle for "soft B") means "lower in pitch". Flat is the opposite of sharp, which is a raising of pitch. In musical notation, flat means "lower in pitch by one semitone (half step)", notated using the symbol which is derived from a stylised lowercase 'b'. For instance, the music below has a key signature with three flats (indicating either E major or C minor) and the note, D, has a flat accidental. { \override Score.TimeSignature #'stencil = ##f \relative c'' { \clef treble \key es \major \time 4/4 des1 } } Under twelve-tone equal temperament, D for instance is enharmonically equivalent to C, and G is equivalent to F. In any other tuning system, such enharmonic equivalences in general do not exist. To allow extended just intonation, composer Ben Johnston uses a sharp as an accidental to indicate a note is raised 70.6 cents (ratio 25:24), and a flat to indicate a note is lowered 70.6 cents. In intonation, flat can also mean "slightly lower in pitch" (by some unspecified amount). If two simultaneous notes are slightly out-of-tune, the lower-pitched one (assuming the higher one is properly pitched) is "flat" with respect to the other. Furthermore, the verb flatten means to lower the pitch of a note, typically by a small musical interval. Flats are used in the key signatures of F major / D minor (B) B major / G minor (adds E) E major / C minor (adds A) A major / F minor (adds D) D major / B minor (adds G) G major / E minor (adds C) C major / A minor (adds F) The order of flats in the key signatures of music notation, following the circle of fifths, is B, E, A, D, G, C and F (mnemonics for which include Battle Ends And Down Goes Charles' Father and Before Eating A Doughnut Get Coffee First). Double flats also exist, which look like (similar to two flats, ) and lower a note by two semitones, or a whole step. { \override Score.TimeSignature #'stencil = ##f \relative c'' { \clef treble \time 4/4 beses1 } } A quarter-tone flat, half flat, or demiflat indicating the use of quarter tones, may be marked with various symbols including a flat with a slash () or a reversed flat sign ().