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(♭♭) double-flat


Double-flats on the staff.

A C double-flat and G double-flat on the staff means you'll play a B flat and F natural, respectively.

Image © Brandy Kraemer

A double-flat is the equivalent of two flats, and lowers a note’s pitch by two half steps. The double-flat symbol (♭♭) is placed before a note like other accidentals.

While single flats usually point to black piano keys, double-flats often point to piano naturals; an Ab is a black key, but Abb is the G natural key (see enharmonic notes).

  • Exceptions to this are Fb and Cb, which point to the E and B natural keys, respectively; and Fbb and Cbb, which are the Eb and Bb keys.

The Purpose of the Double-Flat

Double-accidentals are not seen in any working key signature. In fact, if there were a key signature after Cb major (which has the maximum seven flats), it would contain a B double-flat (learn more about theoretical key signatures).

But in everyday notation, double-flats are necessary in certain scenarios. Suppose you were composing in the key of Cb major (which puts a flat on every note) and wanted to write a G natural in a measure or passage containing a lot of Gb’s. Instead of alternating between writing G natural and G flat, you could indicate the tone of G by writing an A double-flat instead.

See (x) double-sharp.

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