A while back Matt Farthing had offered to teach a bunch of us how to play the guitar in the School lunch break. It eventually dissolved once we were past he basics, but I did have a chat to Matt about the musical scale and he mentioned something I wasn't familiar with: "each note on a keyboard rises one 1/2 note counting the sharps". This led to a related problem; where's the sharp key between the B&C and E&F? If the white notes are usually a full tone apart, why does it sound natural going up the scale only playing the white notes? Wouldn't there be a marked difference when you hit F and C? Is this just what we are used to?
I dug up some stuff on the net, but nothing really got to the bottom of the problem. Lots of music theory, but mostly history or the blanket statement "Here's C, and here's a chord". I then found Jeff's music theory page and a whole lot of maths harmonics clicked in to make sense. I still didn't know what happened to the missing black key, but it shows why there is a discrepancy between the spacing of the notes. It seems odd that the tonal equidistance of the chromatic scale works so well when translated to 2,2,1,2,2,2,1.