Music notation glossary · Accidentals
Double flat
two semitones lower
As a Unicode character — to paste into text, spreadsheets or chat. Whether it appears depends on the font.
In the score
What it means
Lowers by a whole tone. In the diminished seventh chord on E flat the top note is B double flat — it sounds like A, but it is a lowered B.
Accidentals
Lowers the note by two semitones. Two flats side by side, and the same logic as the double sharp, only downwards: on the keyboard the note has a far simpler name, but in the context of the key that name would be wrong. Rare, and where it appears, for good reason.
First the note without a sign, then the same note with it
Related pages
Anotona does this for you
Photograph a page of sheet music or play the melody — Anotona finds the key, engraves the notes and transposes them into any other. Free.
See AnotonaEvery note on this page is computed, not typed in — following the rule that also makes F# major spell its seventh degree E#, not F.