PITCH-SHIFTING

5 September 2008

In music, keys are tied to pitches.

And although that might sound difficult, it’s not. Really.

Concert pitch is measured in Hertz or cycles per second, and since 1936, the note A above middle C is pegged at a frequency of 440Hz.

  • There is even an international standard for this (ISO16:1975) — get it here.

You are not even supposed to care about this, you are not even supposed to know about this.  It is a standard, a benchmark, a LAW, taken as read — this is a given — except…

Sometimes a piece of recorded music is slowed down or speeded up, and A4 is no longer 440Hz, and in fact is between the tone and the next semitone — in no man’s land.

I bloody hate that.

For example, my wife noticed that on the Liberty X CD (Being Somebody, 2003, V2) the third track is out of standard pitch. It turned out to be almost exactly between F#m and Gm. A quarter tone! So should it be higher in pitch, the G minor — or lower and F# minor? Which was the original key when they recorded it? Well, the second track, “Jumpin” is G# minor — and so’s the fifth track, “Watcha Doin Tonight?”, so I figured it might be a good bet that it was G minor.

So what I do is rip my CDs to an MP3s (or download the MP3s; whatever), then change the pitch in Audacity (free software) using skill and judgement and a guitar correctly tuned to concert pitch, and then export to MP3 again.

You needed to get LAME so that Audacity would let you export to MP3 fromat, but the results were superb — an altered pitch, without altering the beats per minute!

Anyways, recently my corrections have been shockingly bad quality… and so I am gutted that I have to save as a huge WAV file and then use the free version of NCH’s “Switch” to make the MP3. It’s an extra step I could do without!

Back at the Liberty X track — the quarter tone up to Gm made the voices sound too high, so I dropped the track to F#m in Audacity, and it was spot on!

What the pluck is the good of doing that to a record — it means you cannot play a piano along with it, and you have to retune your guitar all the time.  This is why it is so difficult for people to learn music by ear! Aaargh!

Having a list of musical frequencies and wavelengths is a must, I canny find anything on the web, so I have nicked the following from an old text book.

The Definitive Frequencies List:

Note Frequency (Hz) Wavelength (mm) voice
C0 16.35 21 000
C#0/ Db0 17.32 19 900
D0 18.35 18 700
D#0/ Eb0 19.45 17 700
E0 20.60 16 700
F0 21.83 15 800
F#0/ Gb0 23.12 14 900
G0 24.50 14 000
G#0/ Ab0 25.96 13 200
A1 27.50 12 500
A#1/ Bb1 29.14 11 800
B1 30.87 11 100
C1 32.70 10 500
C#1/ Db1 34.65 9 960
D1 36.71 9 400
D#1/ Eb1 38.89 8 870
E1 41.20 8 370
F1 43.65 7 900
F#1/ Gb1 46.25 7 460
G1 49.00 7 040 sub-bass, contrabass, or  basso profundo:
lower than G1
G#1/ Ab1 51.91 6 650
A2 55.00 6 270
A#2/ Bb2 58.27 5 920
B2 61.74 5 590 Tenor: B2 – G4

Operatic Tenor: B2 – C5

C2 65.41 5 270 Bass: C2 – C4
C#2/ Db2 69.30 4 980
D2 73.42 4 700
D#2/ Eb2 77.78 4 440
E2 82.41 4 190 Operatic Bass – Basso: E2 – F4
F2 87.31 3 950 Operatic Baritone: F2 – G4

Baritone: F2 – F4

F#2/ Gb2 92.50 3 730
G2 98.00 3 520
G#2/ Ab2 103.83 3 320
A3 110.00 3 140 Mezzo- Soprano: A3 – F5
A#3/ Bb3 116.54 2 960
B3 123.47 2 790
C3 130.81 2 640
C#3/ Db3 138.59 2 490
D3 146.83 2 350
D#3/ Eb3 155.56 2 220
E3 164.81 2 090 Alto: E3 – E5
F3 174.61 1 980 Operatic Contralto: F3 – A5
F#3/ Gb3 185.00 1 860
G3 196.00 1 760 Operatic Mezzo- Soprano: G3 – B5
G#3/ Ab3 207.65 1 660
A4 220.00 1 570
A#4/ Bb4 233.08 1 480
B4 246.94 1 400
“Middle” C4 261.63 1 320 Bass: C2 – C4

Soprano C4- A5

Operatic Soprano: C4 – C6

C#4/ Db4 277.18 1 240
D4 293.66 1 170
D#4/ Eb4 311.13 1 110
E4 329.63 1 050
F4 349.23 988 Operatic Bass – Basso: E2 – F4

Baritone: F2 – F4

F#4/ Gb4 369.99 932
G4 392.00 880 Operatic Baritone: F2 – G4

Tenor: B2 – G4

G#4/ Ab4 415.30 831
A5 440.00 784 Operatic Contralto: F3 – A5

Soprano C4- A5

A#5/ Bb5 466.16 740
B5 493.88 699 Operatic Mezzo- Soprano: G3 – B5
C5 523.25 659 Operatic Tenor: B2 – C5
C#5/ Db5 554.37 622
D5 587.33 587
D#5/ Eb5 622.25 554
E5 659.26 523 Alto: E3 – E5
F5 698.46 494 Mezzo- Soprano: A3 – F5
F#5/ Gb5 739.99 466
G5 783.99 440
G#5/ Ab5 830.61 415
A6 880.00 392
A#6/ Bb6 932.33 370
B6 987.77 349
C6 1046.50 330 Operatic Soprano: C4 – C6
C#6/ Db6 1108.73 311 sopranino: higher than C#6
D6 1174.66 294
D#6/ Eb6 1244.51 277
E6 1318.51 262
F6 1396.91 247
F#6/ Gb6 1479.98 233
G6 1567.98 220
G#6/ Ab6 1661.22 208
A7 1760.00 196
A#7/ Bb7 1864.66 185
B7 1975.53 175
C7 2093.00 165
C#7/ Db7 2217.46 156
D7 2349.32 147
D#7/ Eb7 2489.02 139
E7 2637.02 131
F7 2793.83 123
F#7/ Gb7 2959.96 117
G7 3135.96 110
G#7/ Ab7 3322.44 104
A8 3520.00 98
A#8/ Bb8 3729.31 93
B8 3951.07 87
C8 4186.01 82
C#8/ Db8 4434.92 78
D8 4698.64 73
D#8/ Eb8 4978.03 69

Based on A4 being 440Hz and The Speed of sound = 345 m/s (which, in the USA is 1130 ft/s or 770 mph)

It is my pet hate when producers depart from the standard pitch system.  They do it on TV when things are over-running, but there really is no need to mess it up when making a pop record — but they do, and it is sloppy work in my opinion.

ears Years ago I used to have a pitch control (speed adjustment knob) on my turntable, and I would make cassette tapes of the corrected music to keep my ears cleansed!

It took me AGES to buy a CD player because I would be unable to pitch correct recordings — until I got a CD player from Richer Sounds complete with a pitch slider control. Result!

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2 Responses to “PITCH-SHIFTING”

  1. Kevin Peacock Says:

    Thanks. I have just got audacity and lame and and am all set now.


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