Abosolute Pitch: Differentiating between B, C and C# in pure pitch recall

By | November 9, 2008

Abosolute Pitch: Differentiating between B, C and C# in pure pitch recallI’ve hit a snag in my absolute pitch recall from memory. Now sometimes when I attempt to sing middle C out of the blue with no external reference, I sing a B note instead.  Once in a while I also sing a C#. Interestingly, I’m always more or less on one of the three notes. I don’t sing in between them. That’s hopeful!

But how do I learn to recognizing the difference between those notes?

What am I trying to do really? I am trying to have memory recall of three different vibrations per second: 246.942,  261.626, and 277.183.

Current method: random quizzes of those three notes during the day to see if I can learn to recognize the difference. Here is a keyboard to use in hearing the difference.

When comparing the notes side by side, it is easy for most people to tell which is higher and which is lower. But what about pitch recall?

More research:

  • In Western music, we an adjusted “tempered” scale. Because of that, the difference is slightly less from a B note to a C note (14.684) than a C note to a C# (15.557).
  • one equal tempered semitone is equal to 100 cents, and so an octave is 1200 cents.
  • Each auditory nerve cell is a little oscillator, tuned to respond to vibrations in a narrow frequency band corresponding to the nerve’s position on the Basilar Membrane.
  • Basilar Membrane contains 30,000 hair/nerve cells along 35 mm length
  • Each octave is an equal shift of about 3.5 mm
  • Each pure tone is localized to a Critical Band of about 1.2 mm.
  • Each pure tone excites about 1300 hair cells covering a 15% frequency range (< minor third).
  • brain can  resolve position and width of pure tone distribution to 1/20 of full width = 0.06 mm = frequency ratio 1.01 or about 29 cents.
  • The ‘just noticeable’ difference [between two pitches] is often defined as 5 cents – NIST
  • James Taylor says using a capo on a guitar can make it sharp by much as 6 to 8 cents
  • There are roughly 20 little tiny steps between a B and C note where you could hear some difference.
  • The human ear can hear sounds between 15 and 20,000 vibrations per second.
  • Human voices can make sounds in the range of 100 Hz to 5,000 Hz. (The record for low is held by Tim Storms who can sing lower than humans can hear at 8 Hz.)
  • An 88 key piano runs from A0 at 27.5 vibrations per second, up to C8 at 4,186.01 vibrations per second.

Here is a chart of musical note frequencies, including the correct frequency for every key on an 88 key piano:

Frequencies of the equal temperament
C / B# 16.352 32.703 65.406 130.813 261.626 523.251 1046.502 2093.005 4186.009 8372.018 16744.036
C# / Db 17.324 34.648 69.296 138.591 277.183 554.365 1108.731 2217.461 4434.922 8869.844 17739.688
D 18.354 36.708 73.416 146.832 293.665 587.330 1174.659 2349.318 4698.636 9397.273 18794.545
D# / Eb 19.445 38.891 77.782 155.563 311.127 622.254 1244.508 2489.016 4978.032 9956.063 19912.127
E / Fb 20.602 41.203 82.407 164.814 329.628 659.255 1318.510 2637.020 5274.041 10548.082
F / E# 21.827 43.654 87.307 174.614 349.228 698.456 1396.913 2793.826 5587.652 11175.303
F# / Gb 23.125 46.249 92.499 184.997 369.994 739.989 1479.978 2959.955 5919.911 11839.822
G 24.500 48.999 97.999 195.998 391.995 783.991 1567.982 3135.963 6271.927 12543.854
G# / Ab 25.957 51.913 103.826 207.652 415.305 830.609 1661.219 3322.438 6644.875 13289.750
A 27.500 55.000 110.000 220.000 440.000 880.000 1760.000 3520.000 7040.000 14080.000
A# / Bb 29.135 58.270 116.541 233.082 466.164 932.328 1864.655 3729.310 7458.620 14917.240
B / Cb 30.868 61.735 123.471 246.942 493.883 987.767 1975.533 3951.066 7902.133 15804.266

Leave a Reply