Thanks to all of you who have answered my question about
harmony of ambient tones !! I'll continue my intagible quest for that
particular sound ;-))  hehe...

I noticed that most the answers deal with the phenomena of sinusoidal
partials...or something. Note that my question was actually rather
about the overall pitch of (very) complex textures used in dronal
electro-acoustic/ambient music. For example: recently I heard a
track made by Voice-of-Eye, called "flotsam suspended in solar wind".
That track has a huge sound with slooow, very rich textures...As the
sound progresses, other sounds can be heard (ethereal processed voices
etc..) fading in and co-altering on pitch with the sounds that are 
on the foreground at that moment. Of course I'm aware that the whole
sound is not mathematically perfect harmonic (fund *2, *3, *4, etc...),
but with many noise components and inharmonic partials, but that's not
the point. The point is that *all* those textures plus the huge reverb
in that Voice-of-Eye track *STILL* and *ALWAYS* sounds very delightful,
typically ambient harmonically in the ear. When I layer textures, too
much 
sounds NOT delightfully harmonic in the ear (doesn't mean that I dislike
atonal, ugly noise, but when I want harmonic sound, then I want harmonic
sound, not inharmonic sound. And vice-versa of course ;-))) )


David.