Sust. MASC. Music. Preceding sign a note to indicate a reversal of this prior to any alteration tonal value. The diction is composed of the name of the letter «b»: be, and 'box', the note indicated by the square shape of the 'b' in this sign, in the musical notation of the middle ages «»if natural. The 'b' round symbolized the note «if» flat, a semitone lower.
