Thinking in keys...

Anybody have any rational explanation to this !? Have faith if you wish... but don't tell me egal tones can create a variety of 'colors' or 'characters'... I really can't understand why it could.

Well, I was a guitarist for many years - I rarely touch the instrument these days, and so I almost exclusively play piano. Call it guitarist's afterglow if you want, but when I sit down at the piano, different keys suggest different moods. On a basic level some are clearly brighter than others. I find that I notice this particular aspect of key changes quite dramatically when I shift the key by half a step.

And though I admit I don't know why or how this effect occurs, I can speculate. Perhaps the resonating frequencies of any key, for instance A 220 hz and it's natural overtones, has some relation (expressed as a ratio) to some primal rhythm, such as a heart beat, that we are inexorably linked to similarly to the way in which we are bound to circadian rhythms. Most likely it's just a crazy thought, but I will agree that the fact of others' experience is in need of a rational explanation.

Some notes are inherently brighter than others on string instruments because of the effects of sympathetic vibrations. On a violin, for example, notes in the harmonic series for G, D, A, and E will be affected by strings vibrating sympathetically; and notes in the harmonic series for F# will be affected by resonances in the body of the violin.

With brass instruments, there are imperfections in the higher harmonics which likewise affect the color of a key.

Well, all I know is that for some melodies, I just enjoy them better in a certain key. I improvised one in E major, which was very soothing and had a certain feel to it. I play it in C major, D major, G major, F major....and it's all not the same. It doesn't give me the same feel. So, therefore, certain keys portray different moods. I have at least a little bit of absolute pitch, though, so that may be why.