D

D is pitch class 2 — a whole tone above C, two semitones along the chromatic cycle. It is a natural letter-name: the white key between C♯/D♭ and D♯/E♭, and the second degree of a C-major scale.

As a pitch class it gathers every D across octaves into one step of the twelve. It is neither sharper nor flatter than its neighbors by nature; the half-steps on either side define its edges.

In major-triad grammar D is the root of D major (D–F♯–A), the perfect fifth of G major (G–B–D), and the major third of B♭ major (B♭–D–F). Alone it stays a pitch class. Three notes of a recognized major chord may open a vessel offering.

Also known as D natural · Re