MIDI MIDI MIDI Note Frequency Note Frequency Note Frequency C1 0 8.1757989156 12 16.3515978313 24 32.7031956626 Db 1 8.6619572180 13 17.3239144361 25 34.6478288721 D 2 9.1770239974 14 18.3540479948 26 36.7080959897 Eb 3 9.7227182413 15 19.4454364826 27 38.8908729653 E 4 10.3008611535 16 20.6017223071 28 41.2034446141 F 5 10.9133822323 17 21.8267644646 29 43.6535289291 Gb 6 11.5623257097 18 23.1246514195 30 46.2493028390 G 7 12.2498573744 19 24.4997147489 31 48.9994294977 Ab 8 12.9782717994 20 25.9565435987 32 51.9130871975 A 9 13.7500000000 21 27.5000000000 33 55.0000000000 Bb 10 14.5676175474 22 29.1352350949 34 58.2704701898 B 11 15.4338531643 23 30.8677063285 35 61.7354126570 C4 36 65.4063913251 48 130.8127826503 60 261.6255653006 Db 37 69.2956577442 49 138.5913154884 61 277.1826309769 D 38 73.4161919794 50 146.8323839587 62 293.6647679174 Eb 39 77.7817459305 51 155.5634918610 63 311.1269837221 E 40 82.4068892282 52 164.8137784564 64 329.6275569129 F 41 87.3070578583 53 174.6141157165 65 349.2282314330 Gb 42 92.4986056779 54 184.9972113558 66 369.9944227116 G 43 97.9988589954 55 195.9977179909 67 391.9954359817 Ab 44 103.8261743950 56 207.6523487900 68 415.3046975799 A 45 110.0000000000 57 220.0000000000 69 440.0000000000 Bb 46 116.5409403795 58 233.0818807590 70 466.1637615181 B 47 123.4708253140 59 246.9416506281 71 493.8833012561 C7 72 523.2511306012 84 1046.5022612024 96 2093.0045224048 Db 73 554.3652619537 85 1108.7305239075 97 2217.4610478150 D 74 587.3295358348 86 1174.6590716696 98 2349.3181433393 Eb 75 622.2539674442 87 1244.5079348883 99 2489.0158697766 E 76 659.2551138257 88 1318.5102276515 100 2637.0204553030 F 77 698.4564628660 89 1396.9129257320 101 2793.8258514640 Gb 78 739.9888454233 90 1479.9776908465 102 2959.9553816931 G 79 783.9908719635 91 1567.9817439270 103 3135.9634878540 Ab 80 830.6093951599 92 1661.2187903198 104 3322.4375806396 A 81 880.0000000000 93 1760.0000000000 105 3520.0000000000 Bb 82 932.3275230362 94 1864.6550460724 106 3729.3100921447 B 83 987.7666025122 95 1975.5332050245 107 3951.0664100490 C10 108 4186.0090448096 120 8372.0180896192 Db 109 4434.9220956300 121 8869.8441912599 D 110 4698.6362866785 122 9397.2725733570 Eb 111 4978.0317395533 123 9956.0634791066 E 112 5274.0409106059 124 10548.0818212118 F 113 5587.6517029281 125 11175.3034058561 Gb 114 5919.9107633862 126 11839.8215267723 G 115 6271.9269757080 127 12543.8539514160 Ab 116 6644.8751612791 A 117 7040.0000000000 Bb 118 7458.6201842894 B 119 7902.1328200980
NOTES: Middle C is note #60. Frequency is in Hertz.
Here is C code to calculate an array with all of the above frequencies (ie, so that midi[0], which is midi note #0, is assigned the value of 8.1757989156). Tuning is based upon A=440.
float midi[127];
int a = 440; // a is 440 hz...
for (int x = 0; x < 127; ++x)
{
midi[x] = (a / 32) * (2 ^ ((x - 9) / 12));
}