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'.[1][2] 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.[3]

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.

Key signatures

Flats are used in the key signatures of

  1. F major / D minor (B)
  2. B major / G minor (adds E)
  3. E major / C minor (adds A)
  4. A major / F minor (adds D)
  5. D major / B minor (adds G)
  6. G major / E minor (adds C)
  7. 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).

Related symbols

Double flats also exist, which look like

double flat
(similar to two flats, ) and lower a note by two semitones, or a whole step. Historically, in order to raise a double flat to a simple flat, it was required to use the notation . In modern scores it is acceptable to simply denote this with a single flat .

\override Score.TimeSignature #'stencil = ##f
\relative c'' {
  \clef treble \key c \major \time 4/4 beses2 bes2
} }

A quarter-tone flat or half flat, indicating the use of quarter tones, may be marked with various symbols including a flat with a slash (

flat stroke
) or a reversed flat sign (
half flat
). A three-quarter-tone flat, flat and a half or sesquiflat, is represented by a half flat and a regular flat (
three quarter flat

\override Score.TimeSignature #'stencil = ##f
\relative c'' {
  \clef treble \key c \major \time 4/4 ceh1 deseh
} }

Although very uncommon, a triple flat (

triple flat
) can sometimes be found.[4] It lowers a note three semitones.


The Unicode character ♭ (U+266D) can be found in the block Miscellaneous Symbols; its HTML entity is ♭. Other assigned flat signs are as follows:

See also


  1. ^ Benward & Saker (2003). Music in Theory and Practice, Vol. 1, p. 6. McGraw-Hill, Seventh edition. "Flat ()—lowers the pitch a half step."
  2. ^ Flat, Glossary, Naxos Records
  3. ^ 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."
  4. ^ Byrd, Donald (September 2016). "Extremes of Conventional Music Notation". Indiana University Bloomington. Archived from the original on 8 March 2010. Retrieved 4 November 2016.