PHP Array of Musical Frequencies

frequencies.php

<?php

/**
 * Musical Notes to Frequency Table
 * 
 * This array contains all of the notes on a piano with their
 * corresponding frequencies. The array is organized into octaves
 * making it easy to loop through and output, for example, an html chart
 * of notes and frequencies.
 *
 * some possibly useful tidbits:
 *
 * * speed of sound at room temperature: 34600 cm/s (or 346 m/s)
 *
 * * wavelength = speed of sound / frequency
 *
 * * a musical fifth is 1.5 times the frequency of the note a 5th below it
 *   (or to be more exact, 1.49830708)
 *
 * @author   Dave Kobrenski <dave@bbmdesigns.com>
 * @link     http://davekobrenski.com
 * @license  http://www.php.net/license/3_01.txt  PHP License 3.01
 */

$notes[0]["A"] = 27.500000000000000; //lowest note on piano
$notes[0]["A#"] = 29.135235094880619;
$notes[0]["B"] = 30.867706328507756;

$notes[1]["C"] = 32.703195662574829;
$notes[1]["C#"] = 34.647828872109012;
$notes[1]["D"] = 36.708095989675945;
$notes[1]["D#"] = 38.890872965260113;
$notes[1]["E"] = 41.203444614108741;
$notes[1]["F"] = 43.653528929125485;
$notes[1]["F#"] = 46.249302838954299;
$notes[1]["G"] = 48.999429497718661;
$notes[1]["G#"] = 51.913087197493142;
$notes[1]["A"] = 55.000000000000000;
$notes[1]["A#"] = 58.270470189761239;
$notes[1]["B"] = 61.735412657015513;

$notes[2]["C"] = 65.406391325149658;
$notes[2]["C#"] = 69.295657744218024;
$notes[2]["D"] = 73.416191979351890;
$notes[2]["D#"] = 77.781745930520227;
$notes[2]["E"] = 82.406889228217482;
$notes[2]["F"] = 87.307057858250971;
$notes[2]["F#"] = 92.498605677908599;
$notes[2]["G"] = 97.998858995437323;
$notes[2]["G#"] = 103.826174394986284;
$notes[2]["A"] = 110.000000000000000;
$notes[2]["A#"] = 116.540940379522479;
$notes[2]["B"] = 123.470825314031027;

$notes[3]["C"] = 130.812782650299317;
$notes[3]["C#"] = 138.591315488436048;
$notes[3]["D"] = 146.832383958703780;
$notes[3]["D#"] = 155.563491861040455;
$notes[3]["E"] = 164.813778456434964;
$notes[3]["F"] = 174.614115716501942;
$notes[3]["F#"] = 184.997211355817199;
$notes[3]["G"] = 195.997717990874647;
$notes[3]["G#"] = 207.652348789972569;
$notes[3]["A"] = 220.000000000000000;
$notes[3]["A#"] = 233.081880759044958;
$notes[3]["B"] = 246.941650628062055;

$notes[4]["C"] = 261.625565300598634; //middle C
$notes[4]["C#"] = 277.182630976872096;
$notes[4]["D"] = 293.664767917407560;
$notes[4]["D#"] = 311.126983722080910;
$notes[4]["E"] = 329.627556912869929;
$notes[4]["F"] = 349.228231433003884;
$notes[4]["F#"] = 369.994422711634398;
$notes[4]["G"] = 391.995435981749294;
$notes[4]["G#"] = 415.304697579945138;
$notes[4]["A"] = 440.000000000000000; //A 440
$notes[4]["A#"] = 466.163761518089916;
$notes[4]["B"] = 493.883301256124111;

$notes[5]["C"] = 523.251130601197269;
$notes[5]["C#"] = 554.365261953744192;
$notes[5]["D"] = 587.329535834815120;
$notes[5]["D#"] = 622.253967444161821;
$notes[5]["E"] = 659.255113825739859;
$notes[5]["F"] = 698.456462866007768;
$notes[5]["F#"] = 739.988845423268797;
$notes[5]["G"] = 783.990871963498588;
$notes[5]["G#"] = 830.609395159890277;
$notes[5]["A"] = 880.000000000000000;
$notes[5]["A#"] = 932.327523036179832;
$notes[5]["B"] = 987.766602512248223;

$notes[6]["C"] = 1046.502261202394538;
$notes[6]["C#"] = 1108.730523907488384;
$notes[6]["D"] = 1174.659071669630241;
$notes[6]["D#"] = 1244.507934888323642;
$notes[6]["E"] = 1318.510227651479718;
$notes[6]["F"] = 1396.912925732015537;
$notes[6]["F#"] = 1479.977690846537595;
$notes[6]["G"] = 1567.981743926997176;
$notes[6]["G#"] = 1661.218790319780554;
$notes[6]["A"] = 1760.000000000000000;
$notes[6]["A#"] = 1864.655046072359665;
$notes[6]["B"] = 1975.533205024496447;

$notes[7]["C"] = 2093.004522404789077;
$notes[7]["C#"] = 2217.461047814976769;
$notes[7]["D"] = 2349.318143339260482;
$notes[7]["D#"] = 2489.015869776647285;
$notes[7]["E"] = 2637.020455302959437;
$notes[7]["F"] = 2793.825851464031075;
$notes[7]["F#"] = 2959.955381693075191;
$notes[7]["G"] = 3135.963487853994352;
$notes[7]["G#"] = 3322.437580639561108;
$notes[7]["A"] = 3520.000000000000000;
$notes[7]["A#"] = 3729.310092144719331;
$notes[7]["B"] = 3951.066410048992894;

$notes[8]["C"] = 4186.009044809578154; //highest note on piano

?>