Spectral mutation is one highly successful way to approach this. The only implementation of spectral mutation in Max/MSP that I am aware of is lp.frim~ in Litter Power, Pro Bundle.

Otherwise, poke around in the examples folder and you may find some inspiration in the Convolution Workshop and Phase Vocoder.

The next release of Litter Power will contain additional objects for sound transformation, but no release date is set as yet.

Best -- Peter

I am just thinking of ideas but one way you could do this is linearly interpolate between FFT bins. You could then crossfade between the two. You would also need to morph the amplitude envelope of the sound as well.

Anthony

Maybe FFTease objects may be of any help ? Just a guess since I must admit I haven't checked them.

Julien.

Thinking of ideas is great, but you are aware that what you're suggesting is exactly what Spectral Mutation in USIM mode does? Or maybe not. Anyway, that is what it does.

ISIM mode works similarly but with a stochastic interpolation. Then you've got the more idiosyncratic but ever-popular UUIM, IUIM, LCM, and WCM giving both cross-fades and totally new results.

Oh, yesterday I forgot to mention that FFTease also has a couple of nifty gradual-transformation-of-sampled-sounds items. Wurf lookin' at.

Which just goes to show that I don't only ever plug my own stuff!-

-- Peter