D-sharp major

What it means

D-sharp major is the major key built on the root D♯. On the circle of fifths it sits nine steps to the sharp side of C major, requiring nine sharp signs in its key signature, including two double sharps for F double sharp and C double sharp.

In sound, D-sharp major is identical to E-flat major, which needs only three flats. On instruments tuned in equal temperament, essentially all modern keyboard and wind instruments, the two keys sound exactly the same, differing only in how the pitches are spelled.

In the notation

The full key signature of D-sharp major has nine sharps: F♯, C♯, G♯, D♯, A♯, E♯, B♯, plus the two double sharps F double sharp and C double sharp. Such a cluster of double sharps makes the notation unusually hard to read, which is why this key is almost never used in its literal spelling.

Musical use

Because D-sharp major belongs to the theoretically possible but practically unused keys, composers and notation software almost always substitute the enharmonically identical and far more legible E-flat major. D-sharp major mainly appears in music theory as an illustration of the outer limits of the circle of fifths, and occasionally as a brief passing key within a heavily sharp-inflected modulating passage.