D Major9 - Research on Harmony - Variation 3

The seventh arrives. Seven notes arching from D2 to F#7 — the second bell-shaped phrase in the series, rising in four. C#5 appears explicitly, the seventh's blue-green adding a cool note to the otherwise warm palette. D2, D3, D4 fill the bass in orange, D5 continues upward, then F#6 and F#7 carry the third into the highest register.

Orange and green form the spine, but blue-green at C#5 shifts the center of the painting. Where other variations live entirely in warm tones, this one holds a pocket of cool color at mid-canvas — the seventh, the note that extends the triad into a richer harmony. Green brightens toward white at F#6 and F#7, the third dissolving.

The only variation where the seventh is heard — blue-green among the oranges, a single cool voice that deepens the chord. The arch rises from black through orange, touches blue-green, and continues to the silver of the third at the keyboard's edge.