Why is there no G# major key?

G♯ major chords exist, so why don’t we ever see a G♯ major key signature? Simply put, it’s too complex for practical use, and there’s an easier way to express it: with the key of A♭ major (its enharmonic equivalent).

Key signatures contain a maximum of seven singular sharps or flats, which we see in the keys C-sharp major and C-flat major, respectively. But, if we were to continue the pattern of sharps, the next key signature would be G-sharp major, which contains an Fx (double-sharp).

Additionally, some of the chords native to G-sharp major would be a bit absurd. Take a look:

  ▪ G# maj: G# - B# - D#

  ▪ A# min: A# - C# - E#

  ▪ B#min:  B# - D# - Fx

  ▪ C# maj: C# - E# - G#

  ▪ D# maj: D# - Fx - A#

  ▪ E# min: E# - G# - B#

  ▪ Fx dim: Fx - A# - C#

G-Sharp Major’s Alter-Ego

For the sake of efficient notation, we can express the same exact scale with only four accidentals by using the key of A-flat major. This key is tonally identical, or "enharmonically equivalent," to G sharp.

A-flat major's scale is as follows:

Ab - Bb - C - Db - Eb - F - G**

**The G in this scale is equal to the Fx.

More on Enharmony:

• The 6 Enharmonic Key Signatures
  If you just know your way around the key signatures, you may have noticed that a few keys – like B-sharp or F-flat major – are seemingly absent while others go by two names.
• The Inefficient Keys
  The circle of fifths only shows the working scales. But if we expand on its pattern, we can see that it’s actually more of an infinite spiral; there’s no end to the possibilities of musical scales and keys.
• Table of Working & Non-Working Keys
  See a clear visual of which keynotes are workable and which would be redundant.