Dsharp

Dsharp, also written as D-sharp or D♯, is a musical note in the chromatic scale of Western music. It is the pitch one semitone above D and one semitone below E. In equal-tempered tuning, D# and Eb occupy the same pitch class and are considered enharmonic equivalents.

Frequency and octave: The exact frequency of Dsharp depends on the octave and tuning reference. In standard 12-tone equal temperament with A4 set to 440 Hz, D#4 is about 311.13 Hz, and D#5 is about 622.25 Hz. The general relationship between adjacent semitones is a multiplication by the twelfth root of two, approximately 1.05946.

Notation and usage: D# can be written as D♯ or Eb. It appears in many scales and chord progressions, and in keys that contain sharps such as B major or F# major; in keys with flats, Eb is often preferred for readability. It is used as an accidental to indicate a raised scale degree, depending on musical context.

In practice, D# is a common pitch name across instruments, from piano to guitar. On keyboard instruments, it lies between the D and E keys, and its exact frequency can vary in tunings that differ from standard equal temperament.