A=440 vs. A=432 and Others

Have you ever heard about this?

When I was searching for a mapping for a keyboard's 88 key's to Hz values, I came across a lot of controversy about A=432 it is the Spiritual Vibration or The Earth's frequency is 8Hz and it somehow connects to 432 and it can increase your energy. OK I'm talking out of my ass here but you get the point.

There is some other frequency that is supposedly the circle of something, the love frequency, it's higher up there. Ah yes 528Hz. It's confusing, because when I started delving into it, it became unapparent if it's implying different intervals as well. (just intonation) I got a little lost there in that sea of information.

Anyway, I effectively created a program that adapted octave 4 of the standard A=440 to A=432 for the SPC700 pitch registers, and I tried listening to my program in A=432. It just sounds a little lower, and a little more dead.

I cannot tell if I like it or not, and I'm currently at the peak of the hill where I am embracing the approach to having a lookup table for intervals for different pitches at different sampling rates. That's a potentially big table, and I don't want this cool Frequency modification to mess up an otherwise fine job. I am intrigued by the proposition of playing at Earth's frequency and whatnot, however if it is not clear whether they are talking about a completely different interval system, I will not simply transpose at the SNES level. I'd rather find a way to transpose the samples before they go into the system. That way, the SNES can keep it's normal intervals working for ANY level of transposition, provided we are still using the "standard" scales, whatever they are called today (12 notes bla bla bla). the chromatic scale. That being said, SNES will continue to look at A=440 since 1) it doesn't matter since samples can be transposed 2) that is contingent upon other things.

bla bla it's a hoax.

If you want looped tone samples, you can't transpose them all around because of the requirement for the loop section length to be a multiply of 16.

The vast majority of people cannot hear the difference between A440 tuning and A432 tuning (unless comparing side by side). The musical meaning of pitch is expressed through the relationship between pitches, not so much by an absolute pitch.

Some people have absolute pitch and may or may not have feelings about A440 or A432 (I have absolute pitch and I don't), but these people are a small minority anyway. When you're talking about retuning an electronic instrument like this, it's an extremely arbitrary thing that makes almost no difference to the music.

In the case of NES (looped noise and DMC) and Game Boy (looped noise), where some channels have an extremely limited selection of pitches, sometimes you have to set your tuning system around the channel with the least precision. Say what you want about the 16-byte loop alignment of BRR, but at least that neatly accommodates the 16-, 32-, or 64-sample periods seen in samples designed for MOD-family formats. NES loop lengths are even crazier: they have to be a multiple of 128 plus 8.

I don't know where these spiritual people get everything from. There is what is called a Schumann resonance that's not 8 but about 7.83 Hz, but that's for electromagnetic radiation, which travels at the speed of light (because, as it were, it is light.) This does not apply to sound, however, because of the lower speed. A resonant frequency depends on the speed at which a wave travels through a medium, and the size of the medium. Since sound is so much slower, Earth's mechanical resonance frequencies would be in the order of hundreds of microhertz, ie a cycle takes several days to complete.
tl;dr, ny mention of 432 Hz as a "spiritual frequency" or "Earth's resonance" is pure bull and based on a poor understanding of physics.

This comment is inadvertently very relevant. You might have heard of the modern "loudness war", where music producers sacrifice dynamic range to get a perceived boost in loudness. Something similar happened back in the 1800s, where the tuning of the root A would gradually get sharper and sharper, since the sharper tuning would sound brighter and thus slightly more appealing. It started out at ~420 Hz but as the trend of raising the A went on, it almost reached 460 Hz. It's not until modern time that reason had its way and people eventually went with the standard A of 440 Hz, as was first recommended in 1834.

Read more: http://www.mozartpiano.com/articles/pitch.php

I've been known to cheat and define tunings centered about 261 5/8 Hz, which results in a sample rate of exactly 8372 Hz for a middle C with 32 samples per period. This produces A = 439.9990 Hz.

Depending on the limitations of the system, and on the music (whether it is equal temperament (which is common) or just intonation, and on what notes you are using and what key it is in), you might also detune to something other than A=440 in order to reduce the relative detuning of the notes. (The music engine in Famicom Hangman does this: I set the base frequency so that the just intonation is perfect, rather than making it 440 Hz or whatever.)

I've tried doing just intonation on the NES. I found that, unfortunately, because the pitch register is a clock divider rather than accumulator (like FDS/N163/SID), your range of perfect tuning is limited to how many prime factors you can stuff in. I was only able to make a limited range of perfect just tuning, in a fairly low octave, before I would have to make compromises and round to the nearest.

http://rainwarrior.ca/projects/nes/harmonic_series_test.nsf

For the NTSC NES I am cheating a bit and makes the pitch a little lower than A=440 Hz so that higher notes sounds overall less wrong. If you don't do this, the lower octaves will sound fines, but the notes in the highest octaves will sound wrong because there is not enough bits for an accurate representation of the frequency you want.
This was not nessesarly for PAL NES.

For more modern consoles (like SNES), such a trick is not needed, and it's safe to assume A = 440 Hz