G-flat minor
Minor key with nine flats (two of them double flats); in practice usually notated enharmonically as F-sharp minor.
What it means
G-flat minor is a theoretical minor key whose key signature would require nine flats, two of them double flats: five single flats (A-flat, D-flat, G-flat, C-flat, F-flat) and two double flats (B and E), each counted as two flats. Its tonic is G-flat; its relative major would be B-double-flat major, which also occurs only in theory.
Musical use
In practice G-flat minor is almost never notated because the number of accidentals makes reading very difficult. Instead one writes the sonically identical key of F-sharp minor with only three sharps. G-flat minor therefore turns up mainly as an example in theory, for instance in connection with the circle of fifths, which beyond six flats leads into keys with double accidentals.
G-flat minor should be distinguished from F-sharp minor, which notates the same notes with three sharps, and from E-flat minor, the practically used minor key with six flats. Enharmonic keys with fewer accidentals are as a rule preferred.
Performance practice
If you meet G-flat minor or similar keys with double accidentals in a piece, transfer them mentally into the enharmonic key with fewer accidentals. This eases reading and protects against errors with the many lowered degrees.