OFFSET
3,1
COMMENTS
In 12-tone equal temperament, when A4 (the fifth A on the Piano keyboard) is tuned to 440 Hz, the frequency of the note D4 (7 semitones below A4) is 440*2^(-7/12) Hz = 293.7 Hz.
LINKS
FORMULA
Equals 220 * 2^(5/12).
EXAMPLE
Frequencies of notes in an octave (Hz):
>--------------------------------------------------
|
| C4 261.6255653005... (A329207)
| +---------------------------------------
>----------| C#4/Db4 277.1826309768... (A329208)
| +---------------------------------------
| D4 293.6647679174... (this seq)
| +---------------------------------------
>----------| D#4/Eb4 311.1269837220... (A329210)
| +---------------------------------------
| E4 329.6275569128... (A329211)
|
>--------------------------------------------------
|
| F4 349.2282314330... (A329212)
| +---------------------------------------
>----------| F#4/Gb4 369.9944227116... (A329213)
| +---------------------------------------
| G4 391.9954359817... (A329214)
| +---------------------------------------
>----------| G#4/Ab4 415.3046975799... (A329215)
| +---------------------------------------
| A4 440.0000000000
| +---------------------------------------
>----------| A#4/Bb4 466.1637615180... (A329217)
| +---------------------------------------
| B4 493.8833012561... (A329218)
|
>--------------------------------------------------
[New layout from Jon E. Schoenfield, Nov 08 2019]
MATHEMATICA
RealDigits[440 1/Surd[2^7, 12], 10, 120][[1]] (* Harvey P. Dale, Aug 01 2021 *)
PROG
(PARI) default(realprecision, 100); 440 * 2^(-7/12)
CROSSREFS
KEYWORD
AUTHOR
Jianing Song, Nov 08 2019
STATUS
approved