piano scale
G Lydian
G1A2B3C♯♯4D5E6F♯7
Major with a raised fourth. The fourth mode of the major scale.
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
GWAWBWC♯HDWEWF♯HG
What is true of it
G Lydian is G, A, B, C♯, D, E and F♯, and back to G.
Its steps are W – W – W – H – W – W – H, where W is a whole step and H a half.
On the same tonic, G major differs from it by exactly one note.
Chords made only of these notes
C♯dimdiminishedC♯m7♭5half-diminished seventhDmajorDmaj7major seventhEmminorEm7minor seventhF♯mminorF♯m7minor seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.