Finally there's something that's done a lot in commercial voiceover
work though not so much in music, called ducking. You need to have an
ability to sidechain in your software or hardware, it's not
universally found. You would be applying the smoothed out dynamic
info from your main track to inversely reduce the amplitude of other
track(s). Generally the manual will tell you about it if you have it.
I guess I do ducking all the time in PD but I never knew the term for
it. Also my software compressor does that too.
I guess I knew all of the stuff you mentioned, though you stated it
much more elequently then it looks in my head. Despite me knowing the
facts your arrangement of thoes facts makes mixing a bit clearer now.
Thanks!