"Gb Major" (or the key of Gb) is a major scale based on Gb, with the pitches Gb Ab Bb Cb Db Eb Ab F. Its key signature has six flats: Bb Eb Ab Db Gb Cc. Its Relative Minor scale is Eb Minor. Its Parallel Minor is Gb Minor, usually replaced by F-sharp minor, since G flat minor, which would have nine flats, is theoretically possible but is not typically used.

The primary chords for any major key are the I, IV and V chords of its corresponding major scale. For Gb Major, the primary chords are: Gb, Cb, Db and Db7. From the primary and secondary chords of a major key, countless songs and chords progressions can be played.

The secondary chords for any major key are the II, III and VI chords of it's corresponding major scale. For Gb Major, the secondary chords are: Abm, Abm and Ebm. From the primary and secondary chords of a major key, countless songs and chords progressions can be played.

Common chord progressions for the key of Gb. Using the primary and seconday chords for the key explore these common chord progressions for the key of Gb.

Harmonic Analysis is the understanding of the functional sequence of chords. It is the process used to analyze the harmonic structure of a progression, song or composition. This analysis is then used to make scale selections for improvisation and chord substitution.