So you want adjust the pitch, but without the speed change?
Of course, that's it!
I play in a band, and we use VLC in our sessions/practice, playing backing tracks and songs mainly. But we have to use other player (AIMP2) when we wanna play some songs that are not tuned in standard. So we have 2 options:
1. Re-tune all our instruments
2. Use AIMP2 to change the pitch.
A lot of bands play in many different tones: standard E, drop D, C#... And it's a pain in our hands to retune our intruments each time we want to play some different material.
I'll tell you how the tuning works, if it can helps:
Music is tuned by tones. Normally, the MINIMUM amount of pitch that you can change is 1/2 tone (0.5).
Why?
Because it's really hard to distinguish a note (for example, note A) and a note 1/3 (0.33) tone higher or lower, or 1/4 (0.25)...
As you may know, there are 7 musical notes: A, B, C, D, E, F and G, or in Latin: Do, Re, Mi, Fa, Sol, La and Si. After G (Si), it comes again A (Do).
Now, between each one of those notes there is 1 tone, EXCEPT AFTER "B" and "E", where is just 1/2 tone. So we got this:
1. A
2. A sharp/B flat
3. B
4. C
5. C sharp/D flat
6. D
7. D sharp/ E flat
8. E
9. F
10. F sharp/ G flat
11. G
12. G sharp/ A flat
Each line sum +1/2 of tone. So between A and A sharp there's 1/2 tone. Between A and B there's 1 tone. Between B and C there's 1/2 tone. Between G and B there's 2 tones. B sharp and E sharp don't exist (well, they would be C and F respectively).
As you see, we have a total of 12 different "sounds".
So, what's the problem?
Well, the standard global tuning is called "Standard E", line 9th (don't mistake with the "standard pitch", which is note A). The problem is that a lot of bands TUNE DOWN their instruments and use D sharp tuning, or D, or C sharp tunings.
Oh, I see, so you would have to tune down/up yours to play it. But... how could it be solved?
It could be easily fixed if VLC had an option that change the pitch "X" 1/2 tones up/down. Nevertheless, some bands, rarely, tune their instruments 1/4 tone up/down. So the perfect feature would be that one that change the pitch in 1/4 of tones.
Nice, but what is 1/2 tone, how can I say to the computer that it must change 1/2 tone?
Well, here comes the frequency. First, you have to know that there are infinite "A" notes. Why? Because once you've reached the G sharp, the next note is A, and you start again. And that's why there are numbers after the notes. For example: A4, C5, F3 sharp, G9... Those numbers stands for the high the note it is. For example, G9 is a G note that is so high. The CENTRAL number is 4. And the standard note is A. So the central/standard pitch is A4. Why? Because A4 is the A in one of the strings of the guitar, and it's a bass string note too. A4 is the central pitch, not too high, not too low.
The number changes after the B. So after B3 (remember it doesn't exist B sharp) it comes C4. After G6 sharp it comes A6.
Ok, so just tell me how many frequency (Hz) is 1/2 tone and I got it
Error! 1/2 tone is not a constant frequency. There's NOT the same frequency between "A4 - A4 sharp/B flat" and "D sharp/ E flat - E".
What? Both of them are 1/2 tone!!!
Yeah! But the frequency varies: between C2 and E2 (2 tones), for example (2 number means low notes), there's much more frequency than between C8 and E8 (as well 2 tones, but much less frequency between them).
What can I do?
There's a formula/ecuation that solve all of this,
BASED in A4 (standard pitch):
frequency = 2^(n/12) x 440
Where "n" means the number of "1/2 tones" you've change. For example, the standard pitch is A4, and this formula is based on it, so lets calculate the frequency of A4 (5th string in a classical/electric 6 string guitar, 4th string in a 4 string bass):
2^(0/12) x 440 = 2^(0) x 440 = 1 x 440 = 440Hz
So A4 is 440Hz. Lets calculate C5:
A4 - A4 sharp/B 4 flat - B4 - C5 (remember the number changes after letter B). So there's 3 semitones.
2^(3/12) x 440 = 523.2 Hz
Now lets calculate 3 semitones DOWN A4 to see if the frequency is the same. A4 - G4 sharp/A4 flat - G4 - F4 sharp/G4 flat:
2^(-4/12) x 440 = 1/(2^(4/12)) x 440 = 349.23Hz
3 semitones UP: 523.2 - 440 = 83.2Hz
3 semitons DOWN: 349.23 - 440 = -90.77HZ
As you can see, the frequency varies: between A7 - A7 sharp there's less frequency than between A1 - A sharp.
Ok, so what I should do?
Just use the formula to get the freq of 6 semitones more, or 19 more.
Sorry if it seems hard to understand, I've tried my best...
