Pure Programmer
Project: Chromatic Scale Frequencies
Compute the frequnecies of the notes in chromatic scale based on the standard piano keys in twelve-tone equal temperament. Print the note names A, A#, B, C, C#, etc. followed by the frequency in Hertz. One command line argument should be passed that indicates the octave on the piano that should be used, 0-7.
See [[Piano key frequencies]]
Output
$ node ChromaticScale.js 0
A0 = 27.5000 Hz
A#0 = 29.1352 Hz
B0 = 30.8677 Hz
C1 = 32.7032 Hz
C#1 = 34.6478 Hz
D1 = 36.7081 Hz
D#1 = 38.8909 Hz
E1 = 41.2034 Hz
F1 = 43.6535 Hz
F#1 = 46.2493 Hz
G1 = 48.9994 Hz
G#1 = 51.9131 Hz
A1 = 55.0000 Hz
$ node ChromaticScale.js 4
A4 = 440.0000 Hz
A#4 = 466.1638 Hz
B4 = 493.8833 Hz
C5 = 523.2511 Hz
C#5 = 554.3653 Hz
D5 = 587.3295 Hz
D#5 = 622.2540 Hz
E5 = 659.2551 Hz
F5 = 698.4565 Hz
F#5 = 739.9888 Hz
G5 = 783.9909 Hz
G#5 = 830.6094 Hz
A5 = 880.0000 Hz
$ node ChromaticScale.js 6
A6 = 1760.0000 Hz
A#6 = 1864.6550 Hz
B6 = 1975.5332 Hz
C7 = 2093.0045 Hz
C#7 = 2217.4610 Hz
D7 = 2349.3181 Hz
D#7 = 2489.0159 Hz
E7 = 2637.0205 Hz
F7 = 2793.8259 Hz
F#7 = 2959.9554 Hz
G7 = 3135.9635 Hz
G#7 = 3322.4376 Hz
A7 = 3520.0000 Hz