[Jun8]

I think an octave up (down) means double (half) the frequency of the tone. The usual explanation, I think, is that the Pythagoreans who invented it found this to be the "most pleasing" ratio.

I wonder if there are user studies to back this claim.

I am also at such a low level, that part of your explanation just goes over my head, i.e. what is chromatic scale? Wikipedia says: "The chromatic scale is a musical scale with twelve equally spaced pitches, each a semitone apart. A chromatic scale is a nondiatonic scale having no tonic due to the symmetry of its equally spaced tones." Now very helpful. I thought there were 7 notes! And I don't know any other terms in that sentence (checking their Wikipedia entries doesn't help either, leads to a loop)

[te_chris]

"The chromatic scale is a musical scale with twelve equally spaced pitches, each a semitone apart. A chromatic scale is a nondiatonic scale having no tonic due to the symmetry of its equally spaced tones."

basically what this is saying is that in western music we have divided an octave (the space between a frequency and exactly double that frequency) into twelve "pitches" that we call notes. non-diatonic refers to the fact that it has no basis in any of the western minor or major scales (the two fundamental western scales) as it covers every note of the octave, thus is circular and beyond definition.

Hope that helps

[krig]

The chromatic scale is basically playing every key, black and white, from one C to the next. Whereas the C major scale is every white key from one C to the next.