So, there is a lot to say. But what to do? One technical difference
between "morphing" and "mixing" is this. _If_ you have two sounds
with a clear formant structure (spectral peaks), the mix would
simply fade out one formant structure and fade up the other,
whereas the "morph" would move the spectral peaks from one profile
to the other. How to do this is not always clear. And whether it
sounds convincing is another question. Trevor Wishart has done a 
lot of work from a perceptual and practical point of view. His 
writings may not be "technical", but they do spell out several of 
the issues involved. Try to get hold of his "On Sonic Art", or 
maybe better, the more recent "Audible Design". There are several 
sections on these and related topics. Both come with example 
tape/cd (and both are privately published, not?). Also, his work
"Tongues of Fire" is largely a showcase for this way of thinking 
about music (transformative).

Try this URL until you get hold of any of these texts:
   http://web.interval.com/~malcolm/AudioMorphing/
It's a brief text, but it mentions some issues, and it does have
a few more references.

cheers,
	re