D Whole Tone — E9 Pedal Steel
Every note of D Whole Tone as a bar position on the E9 neck's ten strings, pedals up — the root ringed each time it recurs, and a button that plays the run.
D Whole Tone is 6 notes to the octave (symmetric family), drawn here across the E9 neck's ten strings with every D marked, so home stays visible from anywhere in the pattern.
Weightless and dreamlike — six equal whole steps with no leading tone, so nothing pulls anywhere. Blurry, floating, and faintly unsettling, like a dream sequence.
Heard in: Impressionist piano (Debussy's "Voiles"), Thelonious Monk's runs, dream-sequence film cues, and the augmented and 7#5 chords it fits in jazz.
On a pedal steel a scale is mostly played with the bar moving, one or two notes at a time, and the pedals supply the notes a bar position lacks. These maps show the neck with the pedals up, so what they light is the ground every pedal move starts from.
Work it in one position before you work it up the neck. A bar that lands a hair short of the marker sounds flat on every string it covers, and the ear hears that long before the run is fast.