U+266D ♭, U+266E ♮ and U+266F ♯ are accidentals used in musical notation to alter the pitch of a note by one semitone. However, they are also frequently used in running text, and even more frequently substituted for ASCII lookalikes due to lack of font support. From Bringhurst’s The Elements of Typographic Style:
Three elementary musical symbols - ♭ ♯ ♮, the flat, sharp and natural - are needed for setting normal texts that make reference to standard European musical pitches and keys (Beethoven’s Sonata Op. 110 in A♭, Ennemond Gaultier’s Suite for Lute in F♯m, the drop from C♯ to C♭, etc). These characters are, however, missing from most text fonts. (The octothorp is not an adequate substitute for the sharp.)
U+266D ♭, U+266E ♮ and U+266F ♯ are accidentals used in musical notation to alter the pitch of a note by one semitone. However, they are also frequently used in running text, and even more frequently substituted for ASCII lookalikes due to lack of font support. From Bringhurst’s The Elements of Typographic Style: