U+266D MUSIC FLAT SIGN

U+266D was added to Unicode in version 1.1 (1993). It belongs to the block Miscellaneous Symbols in the Basic Multilingual Plane.

This character is a Other Symbol and is commonly used, that is, in no specific script.

The glyph is not a composition. It has a Ambiguous East Asian Width. In bidirectional context it acts as Other Neutral and is not mirrored. In text U+266D behaves as Ambiguous regarding line breaks. It has type Other for sentence and Other for word breaks. The Grapheme Cluster Break is Any.

The Wikipedia has the following information about this codepoint:

In music, flat, or bemolle (Italian: "soft B") means "lower in pitch". In music notation, the flat symbol, ♭ derived from a stylised lowercase "b", lowers a note by a half step. Intonation or tuning is said to be flat when it is below the true pitch.

Flat accidentals are used in the key signatures of F major/D minor, B-flat major/G minor, E-flat major/C minor, A-flat major/F minor, D-flat major/B-flat minor, and the less frequently used keys of G-flat major/E-flat minor, C-flat major/A-flat minor. 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♭. A mnemonic for this is: Before Eating A Doughnut Get Coffee First.

The Unicode character ♭ (U+266D) can be found in the block Miscellaneous Symbols; its HTML entity is ♭.

Under twelve tone equal temperament, C-flat for instance is the same as, or enharmonically equivalent to, B-natural (B♮), and G-flat is the same as F-sharp (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.

Double flats also exist, which look like (similar to two flats, ♭♭) and lower a note by two semitones, or a whole step. Less often (for instance in microtonal music notation) one will encounter half, or three-quarter, or otherwise altered flats. The Unicode character (U+1D12B) in the Musical Symbols block represents the double-flat sign.

Although very uncommon and only used in modern classical music, a triple flat () can sometimes be found. It lowers a note three semitones.

A half flat, indicating the use of quarter tones, may be marked with various symbols including a flat with a slash () or a reversed flat sign (). Play  A three-quarter flat, or sesquiflat, is represented by a half flat and a regular flat ().