"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.

Major and Minor Harmonized Chord Charts are used for while doing a Harmonic Analysis (HA). Shows triads and 4-part chords for ALL 15 major and minor keys. "Yes, Virginia there are 15 keys."

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.

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.