guitar scale
F♯ Lydian
F♯1G♯2A♯3B♯♯4C♯5D♯6E♯7
Major with a raised fourth. The fourth mode of the major scale.
The same sounds spelled from the other side are G♭ Lydian.
Written out
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
F♯WG♯WA♯WB♯HC♯WD♯WE♯HF♯
What is true of it
F♯ Lydian is F♯, G♯, A♯, B♯, C♯, D♯ and E♯, and back to F♯.
Its steps are W – W – W – H – W – W – H, where W is a whole step and H a half.
It costs 7 alterations to write — near the limit of what a key signature can carry.
On the same tonic, F♯ major differs from it by exactly one note.
Across the first twelve frets of the guitar its notes fall in 42 places, which is what makes a scale a shape rather than a list.
Chords made only of these notes
C♯majorC♯maj7major seventhD♯mminorD♯m7minor seventhF♯majorF♯maj7major seventhG♯majorG♯7dominant seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.