The sound of music

This should be of interest to anyone remotely interested in music theory. At first I wasn’t going to post it, but I have to get it out of my mind. I’m going to leave out some details to keep it unrelated to my practice.

If you’ve ever studied music (modern music in the West anyway), you might have asked yourself why the most common scale – the C major diatonic scale – has such a strange setup. A4 (the A above middle C) is at 440 Hz, and the frequencies of most pairs of adjacent notes (whole steps) are separated by a multiplicative factor of the sixth root of two, except for two (half steps E-F and B-C) which are only separated by the twelfth root of two.

Seems pretty arbitrary, doesn’t it? Probably sounds so good because we’re just used to it.

But what if some ancient cultures (e.g., the Hindus) claimed to hear seven distinct notes while meditating, starting with our middle C, with the only difference being that the A was 432 Hz, instead of 440 (a recent change, it turns out)?

And what if meditators even today sometimes stumbled upon those original frequencies, "hearing" them quite distinctly, persistently, and unmistakably? Well that would be pretty neat, now wouldn’t it?

edit: a little searching reveals it was first 'invented' by the Greeks (see 'Lydian mode'), but I have my suspicions that it was known even earlier...