flat sign
In music notation, the symbol ♭ that lowers a note by a semitone. Compare with 嬰記号 (sharp sign).
See also: 嬰記号
In this score, the B note has a flat sign.
Compound of 変 (へん, 'change' or 'flat' in musical context) and 記号 (きごう, 'symbol'). The musical sense of 変 is a specialized use.