piano scale
D Lydian
D1E2F♯3G♯♯4A5B6C♯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
DWEWF♯WG♯HAWBWC♯HD
What is true of it
D Lydian is D, E, F♯, G♯, A, B and C♯, and back to D.
Its steps are W – W – W – H – W – W – H, where W is a whole step and H a half.
On the same tonic, D major differs from it by exactly one note.
Chords made only of these notes
Found by testing every chord in the catalogue against these 7 sounds, not chosen.