Question: I am learning the Schubert Impromptu Op. 90, No. 3. Everything was going great until page 5. That’s when the double flats came into play. I need help on identifying those double flats… I seem to have gone brain-dead.

– Kat (Huntsville, Alabama, USA)

Albert’s reply: Double flats (and double sharps) aren’t as scary as they look. Accidentals (sharps and flats) simply alter the white key reference notes by a half step.

A half step is the very next key on the piano. (Half steps and whole steps are explained in detail in the articles How to Play a Piano Scale and Music Modes and the History of the Piano Keyboard.)

Double flats lower the reference note (the corresponding white key on the piano) by two half steps (or one whole step). Similarly, double sharps raise the reference note by two half steps.

Here is the excerpt from Schubert’s Impromptu in G-flat major, with all double flats highlighted:

Remember the rule that all sharps and flats introduced anywhere in the measure are retained throughout the measure – that’s why the second A double flat in measure 35 and E double flat in measure 36 are also highlighted, even though there’s no double flat sign immediately preceding them.

To find A double flat on the piano keyboard, start with the white key reference note A. Moving down two half steps, A double flat coincides with the note G. A double flat and G are thus enharmonic – different notes played by the same key on the piano.

You’re beyond the beginning stages, but accidentals and double accidentals are something I cover extensively in my DVD and workbook course, How to Read Sheet Music. I’d recommend the course to you only if you’re not yet able to recognize notes on the staff and find them on the keyboard immediately, without the slightest hesitation – you may well be past that stage. Otherwise you might take a look at the Piano Theory section of key-notes as a quick refresher.