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Fig. 1 · G# double harmonic · first 12 frets

guitar scale

G♯ double harmonic

G♯1A♭2B♯3C♯4D♯5E♭6F𝄪7

Two augmented seconds in one scale, one above the tonic and one below the octave.

The same sounds spelled from the other side are A♭ double harmonic.

on ukuleleon piano

Written out

Fig. 2 · G# double harmonic, ascending

Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.

The step pattern

G♯HAW+HB♯HC♯WD♯HEW+HF𝄪HG♯

What is true of it

G♯ double harmonic is G♯, A, B♯, C♯, D♯, E and F𝄪, and back to G♯.

Its steps are H – W+H – H – W – H – W+H – H, where W is a whole step and H a half.

Written correctly it needs 6 alterations, F𝄪 among them. That is what the letters force, and it is also why nobody writes music in this key: the same notes spelled from the other side are easier to read.

On the same tonic, G♯ harmonic major differs from it by exactly one note.

Across the first twelve frets of the guitar its notes fall in 46 places, which is what makes a scale a shape rather than a list.

Chords made only of these notes

C♯mminorC♯dimdiminishedEaugaugmentedG♯majorG♯augaugmentedG♯maj7major seventhAmajorAmminor

Found by testing every chord in the catalogue against these 7 sounds, not chosen.

Other scales on G♯

G♯ Phrygian dominantexoticG♯ Lydian dominantexoticG♯ alteredexoticG♯ majormajorG♯ natural minorminorG♯ harmonic minorminor

C dbl harmC♯ dbl harmD♭ dbl harmD dbl harmD♯ dbl harmE♭ dbl harmE dbl harmF dbl harmall 374