D (D-sharp) or re dièse is the fourth semitone of the solfège.It lies a chromatic semitone above D and a diatonic semitone below E, thus being enharmonic to mi bémol or E. However, in some temperaments, it is not the same as E. E is a perfect fourth above B, whereas D is a major third above B.
When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the D above middle C (or D4) is approximately 311.127 Hz.[1] See pitch (music) for a discussion of historical variations in frequency.
| Scientific designation | Helmholtz designation | Octave name | Frequency (Hz) | |
|---|---|---|---|---|
| D−1 | D͵͵͵ or ͵͵͵D or DDDD | Subsubcontra | ||
| D0 | D͵͵ or ͵͵D or DDD | Subcontra | ||
| D1 | D͵ or ͵D or DD | Contra | ||
| D2 | D | Great | ||
| D3 | d | Small | ||
| D4 | d | One-lined | ||
| D5 | d | Two-lined | ||
| D6 | d | Three-lined | ||
| D7 | d | Four-lined | ||
| D8 | d | Five-lined | ||
| D9 | d | Six-lined | ||
| D10 | d | Seven-lined |