Back to alphabetical overview – click here

A double flat (𝄫) is an accidental that lowers a note by two semitones (one whole step). It is used to preserve correct musical spelling in scales, chords and harmonic progressions.

What is a double flat?

A double flat lowers the written note by two semitones. For example, B double flat (B♭♭) sounds the same as A in equal temperament, but the spelling is retained because the note functions as a modified form of B within the harmonic context.

Double flats appear mainly in advanced music theory, classical scores and complex harmonic writing, where accurate note spelling is essential.

How is a double flat used in piano playing?

Double flats are uncommon in popular music but occasionally appear in advanced classical and jazz notation. When reading a double flat, simply lower the written note by two semitones while remembering that the unusual spelling serves a theoretical purpose.

Understanding double flats improves your ability to read complex scores and strengthens your knowledge of harmony, notation and key signatures.