In music, flat means lower in pitch. It may either be used generically, meaning any lowering of pitch, or refer to a particular size: lowering pitch by a chromatic semitone. A flat is the opposite of a sharp () which raises pitch by the same amount that a flat lowers it.

Quick Facts ♭, In Unicode ...
Flat (music)
In UnicodeU+266D MUSIC FLAT SIGN (♭)
Different from
Different fromU+0062 b LATIN SMALL LETTER B
Related
See alsoU+1D12B MUSICAL SYMBOL DOUBLE FLAT
U+266F MUSIC SHARP SIGN
Close

The flat symbol () is used in two ways: It is placed in key signatures to mark lines whose notes are flattened throughout that section of music; it may also be an "accidental" that precedes an individual note and indicates that the note should be lowered temporarily, until the following bar line.

Pitch change

The flat symbol, , is a stylised lowercase ‘b’ , derived from Italian be molle for "soft B" and German blatt for "planar, dull". It indicates that the note to which it is applied is played one semitone lower, or in modern tuning exactly 100 cents.[1][2]

In traditional and modern microtonal temperaments the size of sharps or flats (chromatic semitones) is normally smaller than the size of the diatonic semitones found between E and F or B and C. In those tuning systems, the size of the shift made by the symbol usually conforms to the smaller-sized lowering of pitch;[lower-alpha 1] however, for some tuning systems it may instead be replaced by a different symbol for raising and lowering pitch, depending on the author's preference and the intricacy of any microtuning involved.[lower-alpha 2]

Flats used in key signatures

More information Number of flats, Major key ...
Order of flats in key signatures
Number
of flats
Major keyFlat notesRelative
minor key
0C majornoneA minor
1F majorBD minor
2B major B, E G minor
3E major B, E, A C minor
4A major B, E, A, D F minor
5D major B, E, A, D, G B minor
6G major B, E, A, D, G, C E minor
7C major B, E, A, D, G, C, F A minor
The last two rows are shaded because those keys are avoided, in
part because they use inconvenient enharmonic notes, colored red.
In 12 TET the key of C major involves pressing the same keys on
a keyboard as the equivalent B major, which only requires 5 sharps.
Close

The order of flats added onto the key signature is

B, E, A, D, G, C, F.

The corresponding order of keys is off by one:

F, B, E, A, D, G, C.

Starting with no sharps or flats (C major), adding the first flat (B) indicates F major; adding the next (E) indicates B major, and so on, backwards through the circle of fifths.

Some keys (such as C major with seven flats) may be written as an enharmonically equivalent key (B major with five sharps in this case). In rare cases, the flat keys may be extended further:

F → Bdouble flat → Edouble flat → Adouble flat → Ddouble flat → Gdouble flat → Cdouble flat

requiring double flats in the key signature. These are called theoretical key signatures, based on the impracticality of their use, rather than the simpler, equivalent key in 12 TET. This principle applies similarly to the sharp keys.

Key signature example

The staff below shows a key signature with three flats (E major or its relative minor C minor), followed by a note with a flat preceding it: The flat symbol placed on the note indicates that it is a D.

Thumb

In 12 tone equal temperament ( 12 TET )[lower-alpha 3] lowering a note's pitch by a semitone results in a note that is enharmonically equivalent to the adjacent named note. In this system, B and A are considered to be equivalent. In most tuning systems, however, this is not the case.

Temporary accidentals

When used as a temporary accidental sign, the flat symbol is placed to the left of the note head.

Thumb

Temporary accidentals apply to the note on which they are placed, and to all subsequent similar notes in the same measure and octave. In modern notation they do not apply to notes in other octaves, but this was not always the convention. To cancel an accidental signature later in the same measure and octave, another accidental such as a natural (♮) or a sharp (♯) may be used.

A double flat (double flat) lowers a note by two semitones, or a whole step.

Thumb

A quarter-tone flat, half flat, or demiflat indicates the use of quarter tones; it 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 demiflat and a whole flat (three quarter flat).

The symbols -, , flat stroke, among others, represent comma flat or eighth-tone flat, or a quarter of a flat (not to be confused with the larger quarter tone).[lower-alpha 4]

Thumb

Although very rarely used, a triple flat (triple flat) can sometimes be found.[3] It lowers a note three semitones, or a whole tone and a semitone.

Thumb

The symbol of a quadruple flat ( double flatdouble flat ),[lower-alpha 5] or beyond, could be used but would be extremely rare in ordinary temperament.[4]

Thumb

Strictly speaking, there are many other related symbols that can appear.

When used as a temporary accidental sign, they apply to the note on which they are placed, and to all subsequent similar notes in the same staff, measure and octave.

Unicode

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

  • U+1D12B 𝄫 MUSICAL SYMBOL DOUBLE FLAT
  • U+1D133 𝄳 MUSICAL SYMBOL QUARTER TONE FLAT

Other notation and usage

  • Historically, raising a double flat to a single flat would be notated using a natural and flat sign (♮♭) or vice-versa (♭♮) instead of the conventional flat sign (♭). In modern notation the leading natural sign is often omitted.
    Thumb
  • To allow extended just intonation, composer Ben Johnston uses a flat as an accidental to indicate a note is lowered 70.6 cents.[5]
  • In environments where the double flat symbol is not supported, or in specific text notation, a double flat is sometimes written as ♭♭, bb, etc. Likewise, a triple flat can also be written as ♭♭♭, etc.

Footnotes

  1. For example, in quarter-comma meantone a flat always lowers a note's pitch by 76.05 cents, and in just intonation a flat commonly lowers a note's pitch by 70.57 cents. This is comparably smaller to the 100 cents lower used in 12 TET, and the 113.7 cents lower used in Pythagorean tuning. In well temperaments, a flat is two or more different sizes, depending on the temperament and where the starting, unflattened note sits on the circle of fifths.
  2. For example, in 53 TET sharps and flats have two or three different sub-levels, and notation for flattening notes varies, but usually involves several different symbols; one of the sets of 53 TET flat symbols is (67.9 cents), half flat (45.3 cents), and (22.6 cents), used both separately and in combinations.
  3. 12 TET is the predominant system of tuning in Western music.
  4. A quadruple flat ( double flatdouble flat ) lowers a note by four semitones or two whole tones in standard tuning.

See also

  • Sharp (music) – Accidental raising the pitch of a note by one chromatic semitone (♯)
  • Electronic tuner – Device used to tune musical instruments

References

Wikiwand in your browser!

Seamless Wikipedia browsing. On steroids.

Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.

Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.