piano scale
B Lydian
B1C♯2D♯3E♯♯4F♯5G♯6A♯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
BWC♯WD♯WE♯HF♯WG♯WA♯HB
What is true of it
B Lydian is B, C♯, D♯, E♯, F♯, G♯ and A♯, and back to B.
Its steps are W – W – W – H – W – W – H, where W is a whole step and H a half.
It costs 6 alterations to write — near the limit of what a key signature can carry.
On the same tonic, B major differs from it by exactly one note.
Chords made only of these notes
C♯majorC♯7dominant seventhD♯mminorD♯m7minor seventhF♯majorF♯maj7major seventhG♯mminorG♯m7minor seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.