D大调是一个基于D音的大调，由D、E、F♯、G、A、B、C♯、和D组成，调号有两个升号。相对小调是b小调，并行小调是d小调。

D major (or the key of D) is a major scale based on D, consisting of the pitches D, E, F♯, G, A, B, and C♯. Its key signature consists of two sharps. Its relative minor is B minor and its parallel minor is D minor.

D major is well-suited to violin music because of the structure of the instrument, which is tuned G D A E. The open strings resonate sympathetically with the D string, producing a sound that is especially brilliant. This is also the case with all other orchestral strings.